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UNIT 1
DATA MANAGEMENT
LEARNING OUTCOMES:
Upon completion of this unit, you are expected to be able to:
gather data, plot data using appropriate scales, and demonstrate an understanding ofindependent and dependent variables and domain and range
design and conduct experiments using statistical methods and scientific inquiry
demonstrate an understanding of concerns and issues that pertain to the collection of data
describe real-world relationships depicted by graphs, tables of values, and writtendescriptions
solve problems by modeling real-world phenomena
determine the accuracy and precision of a measurement
determine and apply formulas for perimeter, area, surface area, and volume
calculate various statistics using appropriate technology, analyze and interpret displays, anddescribe relationships
analyze statistical summaries, draw conclusions, and communicate results about distributionof data
determine whether differences in repeated measurements are significant or accidental
explore measurement issues using the normal curve
calculate and apply mean and standard deviation, using technology to determine if variationmakes a difference
create and analyze scatter plots using appropriate technology
determine and apply the line of best fit using linear regression with technology
construct and analyze graphs relating two variables
use interpolation and extrapolation and equations to predict and solve problems
MATHEMATICS 10
PAGE 16 CORRESPONDENCE STUDY PROGRAM
DATA MANAGEMENT
UNIT 1 INTRODUCTION:In today's society we are often over-burdened with an abundance ofinformation and numbers concerning various topics which may or may notbe relevant to one's everyday life. This information is often used to makedecisions. There is a need to manage information overload in an efficientmanner to aid in the decision making process and ensure that informationoverload does not occur. This gives rise to one of the newest branches ofmathematics known as data management or statistics. Studying datamanagement provides us with the necessary knowledge, skills and attitudeto collect, organize, represent, display, and analyze data in both an efficientand effective manner. Overall, you will learn when a data set has a pattern,it can be modeled and verified using mathematical representation such asstatistical measure, a graph, or a function. In addition, you will explore yourlevel of confidence in this representation and any predictions or conclusionsyou draw about the data.
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 17
SECTION 1: VARIABLES AND
RELATIONSHIPS
In this lesson you will look at the concept of a
variable and relationships between variables in
more detail. In any relationship, factors that
change are called variables. When a change to one
variable causes a change in another variable, a
cause-and-effect relationship exists between the
variables. The independent variable is a factor that
affects another factor in an experiment or
relationship. The dependent variable is the factor
that is affected by other factors in an experiment
or relationship.
Scientists carefully design experiments to
study which factor has the greatest effect on a
particular situation. An independent variable
is selected to study and an experiment is
designed to change only that variable. All
other variables are held constant. A
controlled variable is any independent variable
whose value is held constant during
an experiment. A controlled experiment is
any experiment in which all but one
independent variable is controlled.
The example problem and solution can be used
as a guide when answering questions involving
relationships.
EXAMPLE PROBLEM
Curling recently became a Winter Olympics
event. The team with the closest rocks to the
center scores in each end of play.
1. The distance the rock moves down the ice
is the dependent variable. It depends on
other factors.
2. Many factors might affect the distance the
rock moves down the ice. Three factors
include:
a) the ice maker's decisions
b) the curler's decisions
c) chance, events outside anyone's control
The dependent variable is affected by the speed
the curler throws the rock, while, the independent
variables are factors which are not affected by the
speed of the rock.
MATHEMATICS 10
PAGE 18 CORRESPONDENCE STUDY PROGRAM
The factors a), b), and c) are independent of the
distance the curling rock attains. The table below
displays independent factors not affected by the
distance the curler throws the rock.
decneulfnisrotcaFrekameciehtyb
decneulfnisrotcaFrelrucehtyb
,srotcafecnahCedistuostneve
lortnocsenoyna
ecifossenilnaelc moorbfongiseddetceles
nospilsrelrucaecieht
"gnilbbep"eci rofdetcelesseohsgnidils
esionnaf
ecifoerutarepmet desueuqinhcetkcah-eht-fo-tuo
ecifossenilnaelcstratsyalpretfa
ytidimuh ehtmfroedilgehtkcah
ehtmorftaehnisnafforebmun
knireht
Mind Map: There are more factors you may
included in the curling example. The diagram
below requires you to develop three additional
independent variables as factors which are not
affected by the distance the curler’s rock is thrown.
See “Focus A, Cause and Effect Relationships” on
page 2 of the text. Complete the following
mind map.
READ AND DO 1
In Mathematical Modeling, Book 1, read
pages 2 to 6. Complete Check Your
Understanding problem 5, page 5 and problem
7, page 6 in the text.
PRACTICE PROBLEM:
Do the following problem for practice and check
your answers in the Solutions Appendix at the
back of this manual.
1. a) List some factors that may affect the speed
at which a parachuter falls to the ground.
b) Identify the factors in which the
parachuter has control over from part a).
Mind Map of Factors that Affect the Curler's Shot Distance
Curler's Shot Distance
DO AND SEND
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 19
SECTION 2: MEASURING
Students are required to collect data in many
situations. The information is analysed,
interpreted and used to calculate additional
information. Two important considerations
student must be mindful of when taking
measurements are accuracy and precision.
Students may generate significant digits using
measurement tools with finer scales. The finer the
scale used to measure, the greater number of digits
a student may record. “Focus C: Accuracy and
Precision”, page 8 permits you to distinguish
between accuracy and precision. Read page 9
under “Counting Significant Digits” and the right
hand column information to learn more about
significant digits. Significant digits will be used in
senior high school science courses.
EXAMPLE PROBLEM
A rectangle, 2.13 by 6.49 is provided with the
dimensions labelled. You are to find the perimeter
and area of the rectangle. The answer is to be
expressed with the appropriate level of precision.
The rules of significant digits are provided with
the examples given:
2.13 cm
6.49 cm
6.49 cm
2.13 cm
Perimeter = 6.49 + 6.49 + 2.13 + 2.13 = 17.24
The answer should be expressed as 17.24 cm. The
least precise value in the problem is the
hundredth’s position.
Area = (6.49)(2.13) = 13.8237
Using the rule for multiplication, you express the
answer as 13.8 cm2. The least number of
significant digits in the factors is three.
RULES OF SIGNIFICANT DIGITS
1. all non-zero digits are considered significant2. any zero located between two significant
digits is considered significant
NOTE:
Leading zeros are not counted when countingsignificant digits and trailing zeros are usuallycounted when they occur after the decimalpoint. Trailing zeros may or may not becounted.
EXAMPLES:
21.7 there are 3 significant digits0.0037 (leading zeros) 2 significant digits1078 there are 4 significant digits350 2 significant digits350.0 (trailing zero after decimal)
4 significant digits10.0034 6 significant digits
ADDITION AND SUBTRACTION
In addition or subtraction you add or subtractthen round the product to the least precisedecimal place or place value.
EXAMPLES:
9.63 + 5.278 + 8.52 = 23.428 = 23.4314.52 - 4.06 = 10.46124.24 + 2.25 = 126.4912.0 + 7.59 = 19.59 = 19.6
MATHEMATICS 10
PAGE 20 CORRESPONDENCE STUDY PROGRAM
PRACTICE PROBLEM:
Do the following problem for practice and check
your answers in the Solutions Appendix at the
back of this manual.
1. Give the answer to each of the following in the
appropriate level of precision (i e. significant
digits)
a) 19.02 + 3.015 + 0.0020
b) 3.0 × 12.6
c) 102 - 2.65
d)
e) 300 + 106
f ) 0.2 × 105
0.00305
0.00021
MULTIPLICATION AND DIVISION
In multiplication and division you multiply or
divide then round the product to the least
number of significant numbers.
EXAMPLES:16.4 × 4.4 = 72.16 = 72
16.3 × 2.19 = 35.697 = 35.7
16.3 × 0.18 = 2.934 = 2.9
16.3 × 5.34241 = 87.081283 = 87.1
READ AND DO 2
In Mathematical Modeling, Book 1, readpages 8 to 11. Complete Check YourUnderstanding problems 13, 14, 16 and 18 onpages 11 to 13 in the text.
You should read the Review of key chapterterms and concepts on pages 47 - 51.
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 21
SECTION 3: DESCRIBING DATA
To make decisions, students need ways to describe
a large set of data. On page 14, read section 1. 3“Describing Data”. A large set of data may be
described using an average. You recall an average is
a single value, calculated from all values in a set,
and used to represent the general significance of a
set of values. In the left column of the text, page
14, the term average is explained. You should
become familiar with the terms mean, median,
and mode. Read “Focus E, Average - A Single
Number Used to Describe or Represent a Set of
Data”, page 15.
The following examples demonstrate mean,
median and mode. These are measures of average.
They are called measures of central tendency. Not
all sets provide useful measures of central
tendency.
MEAN EXAMPLE
The set of numbers include:
8 + 7 + 12 + 4 + 6 + 5 = 42
Adding the set numbers provides a totalof 42.
Dividing the total of all set numbers by 6,(there are six numbers in this set) equals42 ÷ 6 = 7. The number 7 is the singlevalue, calculated by dividing. It representsthe general significance of the set ofnumerical values. The mean number is 7.
MEDIAN EXAMPLE
The set of numbers include:
1, 2, 4, 6, 8, 10, 12
The median is 6. It is the middle number.If there are an even set of numbers themedian is the mean (average) of the two"middle" numbers.
MODE EXAMPLE
The set of numbers include:
1, 2, 4, 6, 8, 8, 8, 8 10, 12
The mode is 8. It is the most frequentlyoccurring number in the set.
EXAMPLE PROBLEM
This set demonstrates how a mean measure of
average can provide an inaccurate measure of
central tendency.
Bart, Bill, Bob, Betty and Barry work for Star
Central. Bart is an accounts payable clerk. He
earns $25 000 annually. Bill is a technician. He
earns $30 000 annually. Bob, in design, earns
$35 000 annually. Betty is the plant manager
earning $45 000 yearly and Barry is the company
president earning $400 000 annually. The mean
salary is $107 000. The company president's
salary skews the result. Barry's salary is an example
of an outlier.
MATHEMATICS 10
PAGE 22 CORRESPONDENCE STUDY PROGRAM
Outliers do not provide an opportunity to calculatean accurate measure of central tendency.
In “Focus F, Data Distribution - Stem-and-LeafPlots”, on page 17, you learn why data is presentedin this format and how a stem-and-leaf-plot isarranged.
Arrange the data in the table below in a stem-and-leaf plot. Place your results in the following stem-and-leaf plot.
3.11 6.21 9.31 2.41 7.51 8.61
4.91 5.61 7.11 3.91 8.91 9.11
4.21 7.41 0.21 1.11 2.31 2.61
7.31 1.61 5.11 1.41 8.91 6.11
2.21 1.31 5.41 3.81 9.61 8.81
Turn to page 18 in Mathematical Modeling andread “Focus G - Box and Whisker Plots”.
Box-and-whisker plots show the distribution andrange of data around a median. Explicit articles are
not shown in the data. The data does show lower
and upper data values and permits the
development of a median in the lower and upper
quartile.
The term outlier was examined in the opposite
column. Outliers may influence results when
confirming the median in a box-and-whisker plot.
Examine the box-and-whisker plots a) and b)
below.
Read “Investigation 2, Reaction Time” on page 14.
The data below was generated following the
procedure in Investigation 2. What is the typical
reaction time in box-and-whisker plot a)? In b)?
210 24
4214
39
2719
a)
b)
16
In a), the typical reaction time is 14. In b), the
typical reaction time is 16. The outliers in box-
and-whisker plot a) are 2 and 42. Are there
outliers in box-and-whisker plot b)? The answer is
yes; the numbers 3 and 27 are outliers in b).
What are the range of values where the middle
50 per cent of the data is distributed? In a), the
range of values where the middle 50 per cent of
the data is distributed is 10 and 24. In b), the
range of values where the middle 50 per cent of
the data is distributed is 9 and 19.
DO AND SEND
metS faeL tnuoC
11 976531 6
21
31
41
51
61
71
81
91
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 23
READ AND DO 3
In Mathematical Modeling, Book 1, read
pages 14 to 23. Complete Focus Questions 3, 9,
10, and 11 on pages 16-20 and Check YourUnderstanding problem 14 on page 21 in
the text.
Complete the following problem. Jamison
surveyed his classmates to find the number of
kilometres each person lives from the school.
Jamison learned his twelve classmates live the
following distances from the school.
You are to complete a box-and-whisker plot below.
Use the data given above. Indicate whether there
are outliers in the data and the range of kilometres
most students live from the school.
8 21 1 3 7 5 0 62 4 2 6 41
To complete the problem above, first calculate the
median, the lower quartile and the upper quartile.
Place each of these numbers and outliers in the
box-and-whisker plot above. Complete a sentence
stating your findings.
SOCCER DISTANCE PROJECT
This project is modeled on the procedure in
Investigation 2 - Reaction Time page 14 of the text.
You organized 40 students to kick a soccer ball.
Each student kicked the soccer ball once. The data
is recorded in table below. The distance measured
is in meters.
kciK#
tnedutSecnatsiD
kciK#
tnedutSecnatsiD
kciK#
tnedutSecnatsiD
kciK#
tnedutSecnatsiD
1 2.41 11 2.5 12 2.81 13 2.51
2 3.21 21 3.81 22 7.91 23 3.71
3 1.51 31 7.51 32 1.71 33 1.61
4 7.81 41 0.31 42 4.11 43 4.71
5 5.41 51 3.91 52 3.91 53 3.61
6 1.31 61 8.71 62 6.31 63 8.61
7 9.61 71 4.41 72 2.02 73 9.51
8 8.21 81 8.61 82 0.42 83 5.02
9 6.51 91 6.61 92 1.41 93 6.81
01 3.61 02 3.91 03 8.31 04 9.71
1. Determine one value that you believe best
determines the distance you will probably
kick the soccer ball. The number you
determine describes your average performance.
This is the distance that you typically kick the
soccer ball.
2. Use the first twenty kicks as the distance you
kicked the soccer ball twenty times. Calculate
the average distance you kicked the soccer ball
with the average distance your forty classmates
kicked the soccer ball. Reflect on the various
ways you used to calculate the average
distance. Write a paragraph to explain the
different methods used to calculate the
average distance.
The data set, given above, is not organized. When
each student kicked the soccer ball the distance
was recorded. When the data is organized you may
begin to see a pattern in the data. You may begin
SOCCER TABLE
DO AND SEND
MATHEMATICS 10
PAGE 24 CORRESPONDENCE STUDY PROGRAM
to see how the values are spread or distributed. Use
the stem-and-leaf plot below to organize the data.
This will make it easier to look for patterns and to
analyze the data. The data is ordered from the least
distance the soccer ball travelled to the greatest
distance. The range of the data is found by
calculating the difference between the least and
greatest distance the soccer ball travelled. You may
begin to see how the values are spread or
distributed by the "shape" of the plot.
metS faeL tnuoC
5
11
21
31
41
51
61
71
81
91
02
42
3. The data in the stem-and-leaf plot you created
is clustered. Examine the data and indicate
where the data is clustered.
a) List the two kicks representing the least
distance the soccer ball travelled?
b) State the two kicks indicative of the
greatest distance the ball travelled.
CREATING A BOX-AND-WHISKER PLOT
4. In the diagram below, there are five number
lines. Use the data from the Soccer Table and
follow steps a) through e) to complete the
number lines with the required information.
Upperextreme
5 10 15 20 25
5 10 15 20 25
5 10 15 20 25
5 10 15 20 25
5 10 15 20 25
1.
2.
3.
4.
5.
Lowerextreme
a) On number line 1, draw an arrow fromthe box marked “Lower extreme” to thepoint on the number line representing thelower extreme and draw an arrow from thebox marked “Upper extreme” to the pointon number line 1 representing the upperextreme.
b) Calculate the median of the data in theSoccer Table. Mark the median on numberline 2.
c) On number line 3, find and mark thelower quartile.
DO AND SEND
DO AND SEND
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 25
d) On number line 4, find and mark the
upper quartile.
e) On number line 5, show where the middle
50 per cent of the data is located.
Construct a box similar to the one below.
Use that box to illustrate where the middle
50 per cent of the data is located.
f ) Now, complete the box-and-whisker plot
below using the Soccer Table data. Your
response should look similar to illustration
13.a) on page 20 of MathematicalModeling, Book 1.
Read Focus H, Data Distribution– Histograms,page 22. The frequency table below illustrates a
bin size of 6 (7 - 1) and the frequency of
distribution of data values within each bin. In the
bin shown, there are 7 data values in the group of
data values.
whisker plot. These plots show how the SoccerTable data is distributed or spread.
The Soccer Table has many pieces ofcontinuous data. A histogram, shown below,has values grouped in bins on the horizontalaxis. The frequency of the data within each binis shown on the vertical axis. This permits youto display the data in graph form.
niB ycneuqerF
7-1 7
21
7
41
7 - 13
13 - 19
19 - 25
Freq
uenc
y
Distance (km)
0 7 13 19 25
7
14
In the frequency table below, the bin size is 5.You are to label the graph with the bin size andfrequency and plot the following histogramusing the Soccer Table data.
0
Freq
uenc
y
Distance (m)
5. You manipulated the data in the Soccer Table
to create a stem-and-leaf plot and a box-and-
DO AND SEND
DO AND SEND
niB ycneuqerF
5-0
01-5
51-01
02-51
52-02
MATHEMATICS 10
PAGE 26 CORRESPONDENCE STUDY PROGRAM
6. Now you will begin to describe the data in the
Soccer Table to compare the distances the
soccer ball was kicked. To describe the data,
calculate the mean and median and use a red
pen to mark each on the histogram you
completed in question 5. Describe the
placement of the values? Are they close, far
apart, identical?
Another way to comment on the distribution
of the set of data is to develop a scale. The
scale is used to rate how the set of values is
distributed. Use the following 0 to 10 scale to
rate how the set of soccer distance kicks is
distributed.
SCALE
0 - no distribution of values
3 - the distribution of values is closely
clustered
5 - spread out to some extent but still
appearing clustered
7 - spread evenly across the range with
outliers
10 - spread with little evidence of clustering.
7. Compare the stem-and-leaf plot and the box-
and-whisker plot you created using data in the
Soccer Table.
READ AND DO 4
In Mathematical Modeling, Book 1, read
pages 24 to 26. Complete Check YourUnderstanding problems 22, 23 and 28, on
pages 24 and 26 in the text.
PRACTICE PROBLEM:
Do the following problem for practice and check
your answers in the Solutions Appendix at the
back of this manual.
1. The mass, in kilograms, of suitcases at the
airport are given in the following table.
51 1 02 7 51 8 3 02
8 61 3 4 31 71 02 9
6 61 22 21 6 91 7 9
01 51 9 81 91 51 41 51
2 82 01 71 7 01 8 8
a) Find the mean, median, and mode for
this data.
b) Create a frequency table for this data
starting at zero and using a bin size of 5.
c) Construct a histogram for the above data
using the frequency table created in part b).
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 27
SECTION 4: DATA SPREAD
DEFINED
Read 1.4 Defining Data Spread, pages 27 to 32, in
your Mathematical Modeling text book. Turn to
page 50 and read the example for 1.4 Defining
Data Spread.
Read Focus I, Standard Deviation: A Measure of
Variation for an introduction to the concepts of
dispersion and standard deviation. See the right
column on page 27 in the textbook to review the
definitions of both terms.
An average provides an introduction to a data set
as an initial step to interpret the data. The
distribution or spread of data provides information
on clusters and outliers and permits an analysis of
patterns in data.
Distribution includes the range and variation of
data. When defining data spread you will see
variation in a data set to permit you to write a
description and definition of the variation. In the
Lobster Catch problem below you will apply these
concepts.
LOBSTER CATCH PROBLEM
The captain of a lobster boat conducted a study
over a four week period. The study was to
determine the best two weeks of the month to
catch lobsters. The data collected is displayed in
LOBSTER CATCH
the table above, right.
1. Does the captain catch more lobster in one
two-week period than the other?
Fill in the blanks in the following sentences.
The mean catch for the first two-week period
is _______ .
The mean catch for the second two-week
period is ________.
2. Is the range of catch during the first two-week
period greater than the second two-week
period?
The first two-week period has a range of
catch of __________.
The second two-week period has a range
of catch of __________.
3. Is there more variation in the first two-week
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6.52 4.91 3.41 4.11 4.31 3.9
3.42 1.81 1.41 7.81 9.51 3.7
7.71 9.61 1.01 8.9 2.11 7.6
7.61 1.41 7.11 9.8 9.21 8.5
MATHEMATICS 10
PAGE 28 CORRESPONDENCE STUDY PROGRAM
period to catch lobsters than the second two-
week period?
eulaVataD morfnoitaiveDnaemeht
)eulavatad-naem(
derauqSnoitaiveD
6.52 65.01-=6.52-40.51 5.111
4.91 63.4-=4.91-40.51 0.91
3.41 47.0=3.41-40.51 55.0
4.11 56.3=4.11-40.51 2.31
4.31 46.1=4.31-40.51 96.2
3.9 47.5=3.9-40.51 9.23
3.42 62.9-=3.42-40.51 57.58
1.81 60.3-=1.81-40.51 63.9
1.41 49.0=1.41-40.51 88.0
7.81 66.3-=7.81-40.51 4.31
9.51 68.0-=9.51-40.51 47.0
3.7 47.7=3.7-40.51 9.95
The table below shows the manual calculation
of the standard deviation. The mean is 15.04.
The deviation from the mean is calculated. The
deviation is the distance each data value is from
the mean.
The mean of the squared deviations is 29.2. The
square root of the mean of the squareddeviations is 5.4.
This suggests that selecting any piece of data
randomly from the first two week lobster catch
is on average, 5.4 kg away from the mean
catch. You may use the TI - 82 or 83 to
calculate standard deviation.
Read question 3 on pages 28 and 29 in your
Mathematical Modeling textbook.
4. Complete the table below by calculating the
deviation from the mean and the mean of the
eulaVataD morfnoitaiveDnaemeht
)eulavatad-naem(
derauqSnoitaiveD
6.52 65.01-=6.52-40.51 5.111
mean deviation fromthe mean
eulaVataD morfnoitaiveDnaemeht
)eulavatad-naem(
derauqSnoitaiveD
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
11.875 -
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UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 29
squared deviation. Use the Lobster Catch data
from the second two-week period.
0 6
12
18 24 30
2468
10
12
The best two weeks of the month to catch lobsters
Freq
uenc
y
Catch
0 6
12
18 24 30
2468
10
12
The best two weeks of the month to catch lobsters
Freq
uenc
y
Catch
a) Graph the first two weeks lobster catch
data in the histogram below.
b) The second two weeks lobster catch data is
to be graphed in the histogram below.
5. Show your calculation of the square root of the
mean of the squares for the second two weeks
lobster catch data below.
Standard Deviation = = _________.
6. Compare the variation in the two sets of
data using standard deviation. Which two
week period had a greater variation?
Explain why.
DO AND SEND 1TOTAL POINTS: 35
UNIT 1 ASSIGNMENT 1Do the following questions and send them to
your marker. The point value for each is at the
end of the question.
In your Mathematical Modeling textbook, do
the following questions, pages 4 - 25.
1. page 4, question 4 5 points
2. page 6, question 8 3 points
3. page 11, question 12 6 points
4. page 13, question 20 3 points
5. page 20, question 13 6 points
6. page 25, question 25 4 points
7. page 25, question 26.a), b) and c). 8 points
In c), you can omit the part where it instructs
you to draw vertical lines for the mean and
median. For your histogram start with zero and
use a bin size of 10.
MATHEMATICS 10
PAGE 30 CORRESPONDENCE STUDY PROGRAM
SECTION 5: LARGE
DISTRIBUTIONS AND THE
NORMAL CURVE
Turn to 1.5 Large Distributions and the NormalCurve on page 33 of the text. Read pages 33 to 39and page 51 to become familiar the mathematicalterms random and frequency polygon.
You may be familiar with the term "the bellcurve". The normal distribution curve is called abell curve. The curve takes it name from the shapeof the curve once data is plotted. As the size ofparticular data sets increase, the graphed data takeson a bell shape.
Companies that conduct public opinion pollingrely on the use of a large sample of data to makereasonably accurate statements about apopulation's views on a particular subject. These
POLLING BIAS
A famous situation where bias entered a pollingsample occurred in the 1948 presidentialelection in the United States. The pollstersfound, from their large sample, that candidateDewey was predicted to defeat candidateTruman by 13 per cent. Truman won theelection by 5 per cent.
Pollster predictions are founded on themathematical understanding that large samplespermit a generalization to be drawn from thesample and applied to the electorate.
Comparing the Shape of Different-Sized Sets of Data.
1. Use the diagram below to create a histogram
0150 170 180 190
2
4
6
8
10
160
Freq
uenc
y
Height (cm)
140 200
Height measurements (cm)Grade 10 girls
0150 170 180 190
5
10
15
20
25
160
Freq
uenc
y
Height (cm)
140 200
Height measurements (cm)Grade 10 girls
30
3. Use a red pen to create a frequency polygon for
the histograms in questions 1 and 2.
4. The mean in Set 1 data is __________.
The median in Set 1 data is _________.
The modes in Set 1 data are ________.
The mean in Set 2 data is __________.
The median in Set 2 data is _________.
The modes in Set 2 data are _________.polls use random sampling to avoid bias.Read pages 33 and 34, Investigation 4,
from Set 1 in Procedure A.
2. Use the diagram below to create a histogram
from Set 2 in Procedure B.
DO AND SEND
DO AND SEND
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 31
5. Write a response to Investigation Questions 1.a)
and b) on page 34.
Read Focus J, The Effect of Sample Size on the Shapeof a Frequency Polygon, on page 34.
In Focus J, you learn that as the sample size
increases (the data values in the set increase) the
histogram, when graphed, will result in a
frequency polygon that is more curved around the
middle of the graph.
See the two example histograms below for an
example of the frequency polygon curve with the
size of a data set. As the bin size decreases, a
frequency polygon will draw more closely to a curve.
The bin size decreases from 6 in the top histogram
to 3 in the bottom histogram.
0 6 18 24 30
2
468
12
Freq
uenc
y
Distribution
These two example histograms show that as the sample size increases the frequency polygon becomes more curved around the middle of the graph
0
5
10152025
Freq
uenc
y
30
3 6 9 12 15 18 21 24 27 30
Distribution
READ AND DO 5
In Mathematical Modeling, Book 1, read
pages 27 to 32. Complete Check YourUnderstanding problems 4, 6 and 8, on pages
30 and 31 in the text.
Read Focus K, Normal Distribution on page 36 tolearn more about the normal curve and propertiesof normal distribution.
1. Do Focus Question 5 and Check YourUnderstanding question 9 on page 37.
2. Complete Check Your Understanding questions10, 12 and 14, on pages 38 and 39.
3. Complete the following five normaldistribution True and False questions.
a) For a normal distribution the mean andmode are the same value. The median isnot the same as the mode but is the sameas the mean.
b) The majority of the data set is clusteredaround the mean.
c) The graph of the data is symmetrical onlywhen the bin size is less than 5.
d) Suppose 420 students enter an paperairplane tossing contest to hit a wall 20 maway. The mean was 15 m and the resultswere normally distributed. The standarddeviation was 2.5 m. The range of flightdistance for 68 per cent of the students istypically 13.5 to 18 m.
MATHEMATICS 10
PAGE 32 CORRESPONDENCE STUDY PROGRAM
e) In a normal distribution outliers fall
outside of 2 standard deviations of
the mean.
PRACTICE PROBLEMS:Do the following problems for practice and check
your answers in the Solutions Appendix at the
back of this manual.
1. A hospital determines that the average stay in
the hospital for pneumonia cases is 7 d with a
standard deviation of 2 d. Assuming a normal
distribution.
a) What percent of the cases stay in between
3 d and 7 d?
b) What percent of the pneumonia cases stay
in longer than 9 d?
2. The Long Life Light Company advertises that
it’s light bulbs have a mean life of 900 h with a
standard deviation of 50 h. Assuming a
normal distribution:
a) What percent of the bulbs will last
between 900 h and 1000 h?
b) What percent of the bulbs will last longer
than 1000 h?
c) If a business purchases 3000 bulbs, how
many can be expected to last less than
850 h?
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 33
SECTION 6: USING DATA
TO PREDICT
Turn to 1.6 Using Data to Predict and read pages
40 to 44. Return to Focus L, Scatter Plots and Linesof Best Fit on page 40 to become familiar the
mathematical terms scatter plot, line of best fit,interpolate and extrapolate. You are now
investigating a relationship between data
representing two variables. You will also be
expected to make predictions about the
relationship between the data values. An
understanding of this information will support
you as you approach the study of functions.
MALE HEIGHT AND AGE
190
170
150
130
110
90
70
50
06 12 18 24 30
Hei
ght
Age
egA )mc(thgieHnaeM
3 55
6 87
9 601
21 811
51 751
81 771
12 381
42 881
72 091
Create a scatter plot of male mean height at each age
Draw a line of best fit
3. Complete Check your Understanding questions
3, 4, 5, 7, 8 and 9 on pages 42, 43 and 44.
4. Complete parts a, b, c, d and e of Putting ItTogether Case Study 1, page 45 regarding
health issues for teenagers.
1. In the Male Age and Height diagram, next
column, the scatter plot of male height and
age is provided. You are to create a line of best
fit to show the relationship between male age
and male height at each age. What is the cause
and effect relationship between male age and
male height? Is it reasonable to extend the
line? Explain. Refer to pages 40 and 41 in the
text before completing your response.
2. Read Investigation 5, Predicting Writing Speedpages 41 and 42 of the text. Complete
Procedure A, B, C, D, E, F, G, and H using the
diagram on the next page.
READ AND DO 5
Complete the following four questions.
MATHEMATICS 10
PAGE 34 CORRESPONDENCE STUDY PROGRAM
15
13
11
9
7
5
3
1
03 5 7 9 11
Num
ber
of w
ords
wri
tten
Number of letters in word
Create a scatter plot of of the mean number of words written and the number of letters in a word.
Draw a line of best fit
drownisretteL fo#naeMnettirwsdrow
3
5
7
9
11
PRACTICE PROBLEM 2
Do the following problem for practice and check
your answers in the Solutions Appendix at the
back of this manual.
1. The following chart shows the final marks in
Math and Physics for 13 students.
tnedutS A B C D E F G H I J K L M
htaMkram
36 25 38 17 35 59 64 68 86 03 08 23 04
scisyhPkram
65 45 68 57 85 78 25 09 66 83 15 11 38
a) Draw a scatterplot of the points with Math
marks on the horizontal axis and draw the
line of best fit.
b) Does there appear to be a relationship
between the plotted points? Describe the
type of relation you believe is occurring.
c) Use your graph to predict a Physics mark
for student N if his/her Math mark is 75.
UNIT 1
CORRESPONDENCE STUDY PROGRAM PAGE 35
DO AND SEND 2TOTAL POINTS: 20
UNIT 1 COURSE PROJECT
Do the following questions and send them to
your marker. The point value for each is at the
end of the question.
BACKGROUND INFORMATION:
You will begin working on a project in this unit
that will involve the use of skills and concepts
acquired in the previous lessons. This project
will continue in each unit to reinforce the topics
covered within that unit. The work in this unit
will be similar to the unit assignments. Send
them to your marker for evaluation.
THAM Incorporated is a Nova Scotia company.
THAM Inc. produces and markets various
mathematical instruments and computer
software. The products are used in business and
educational settings. Some of the items include
graphing calculators, math sets, computer
software for engineering and surveying
applications, and clinometers. THAM Inc. has
offices and retail outlets in Halifax, Moncton,
Montreal, Toronto, and Vancouver.
You have been recently hired by THAM Inc. as a
marketing consultant. Throughout this manual
you will investigate several relationships that exist
within THAM Inc. and extend your
mathematical knowledge at various intervals to
help solve problems presented to the corporation.
Your first assignment as marketing consultant is to
answer the following:
1. THAM Inc. is interested in monitoring the
sales of their graphing calculators. Like many
products there are times when sales rise and
when sales fall. Make a list of possible
independent variables which could affect the
number of graphing calculators sold
(dependent variable). 3 points
2. The table below shows the graphing calculator
sales for each month in the 2002 operating
year for each office.
htnoM xafilaH notcnoM laertnoM otnoroT revuocnaV
yraunaJ 24 04 36 89 59
yraurbeF 83 54 05 08 38
hcraM 05 05 06 87 09
lirpA 35 84 07 28 29
yaM 94 84 56 57 57
enuJ 26 56 28 69 001
yluJ 03 53 65 96 17
tsuguA 23 53 25 06 07
rebmetpeS 87 57 09 011 09
rebotcO 26 06 18 19 68
rebmevoN 85 94 27 87 87
rebmeceD 07 07 39 001 99
Which office appears to have the most
consistent sales? Explain how you derived
your answer. If a graph was used please
include it in your write-up. 8 points
MATHEMATICS 10
PAGE 36 CORRESPONDENCE STUDY PROGRAM
3. Does there appear to be any month(s) where
sales have increased significantly at all offices?
Explain why a sales increase may have
happened in these months. 2 points
4. Suppose you were given a sales report with 68
calculators sold in a month. The top of the
report is missing that gives the office location.
Which office is this report most likely from?
Explain? 2 points
5. THAM Inc. has just received an order for
1500 math sets. Their progress at the
Moncton office for the first week is shown.
syaDforebmuN steSforebmuNdetelpmoC
1 79
2 502
3 723
4 344
5 835
6 366
7 597
Use the data in the table to create a scatter plot
to show the relationship between the number
of days and the number of sets completed and
draw the line of best fit. 4 points
6. Using your graph, predict the number of days
to needed to fill the order. 1 point