Unit 15Data Collection

Biased Questions

Rewrite these questions so as to make each of them unbiased.

1.Do you think that we do enough work in school and that homework is unnecessary?

2.Should the Government spend more money on education?

3.Should the Prime Minister avoid paying income tax?

4.Should nurses get a bigger pay rise that politicians?

5.Should there be more sport on TV?

6.Should we still belong to the Commonwealth?

7.Do you agree that Arsenal are clearly the best football team in the world?

8.Should we abandon our Jamaican dollar and adopt the US dollar for our currency?

Unit 15Data Collection

Survey Results

Lance thinks that students who come to school by bus are more likely to be late that those who do not travel by bus.

In order to test whether or not this is true, he carries out a survey of 100 students from Grade 7 for 5 consecutive Tuesdays.

a)Do the results show Lance is correct?

b)How could the survey be improved?

Method of Travel

Number of Students

Number Late % late

Route Taxi 150 40

Bus 50 10

Car 100 22

Walk 200 25

TOTAL 500 97

Lance thinks that students who come to school by bus are more likely to be late that those who do not travel by bus.

In order to test whether or not this is true, he carries out a survey of 100 students from Grade 7 for 5 consecutive Tuesdays.

c) A student is selected at random from Grade 7

What is the probability that this student walk to school on Tuesday?

Method of Travel

Number of Students

Number Late % late

Route Taxi 150 40

Bus 50 10

Car 100 22

Walk 200 25

TOTAL 500 97

??

?

Unit 15Data Collection

Sampling

There are 12 teacher is a small school. A sample size of 4 is to be selected from this population.

A ) SYSTEMATIC sample

Here we collect, for example, every third teacher from the sample, giving:

TEACHERS

1. Mrs Powell

2. Mrs Grant

3. Mrs Clarke

4. Mrs Bailey

5. Mrs Miller

6. Mr Gordon

7. Mr Francis

8. Mr Brown

9. Mr Wright

10. Mr Gray

11. Mr Davis

12. Mr Lawrence

Mrs ClarkeMrs Clarke

Mr GordonMr Gordon

Mr WrightMr Wright

Mr LawrenceMr Lawrence

B ) RANDOM sample

Here we need to use a list of random

numbers. Beginning at the top left hand

corner and working down the column, you

take pairs of numbers using only numbers

less than 12.

The first number is

and the teacher is

The second number is

and the teacher is

TEACHERS

1. Mrs Powell

2. Mrs Grant

3. Mrs Clarke

4. Mrs Bailey

5. Mrs Miller

6. Mr Gordon

7. Mr Francis

8. Mr Brown

9. Mr Wright

10. Mr Gray

11. Mr Davis

12. Mr Lawrence

80 02 86 03

23 90 18 56

84 34 73 51

31 98 73 65

28 73 32 83

52 70 53 23

47 14 69 68

15 45 05 18

59 79 80 51

75 11 14 10

Mrs GrantMrs Grant0202

1111

Mr DavisMr Davis

The third number is

and the teacher is

The fourth number is

and the teacher is

0505

0303Mrs MillerMrs Miller

Mrs ClarkeMrs Clarke

Unit 15Data Collection

Distance Chart

a) What is the distance from:i. Lucea to Rio Bueno?

ii. Hectors River to Spanish Town?

b) Which two places are furthest apart?

89 km89 km

90 km90 km

Hectors RiverHectors RiverBlack RiverBlack River and

c) You drive from Spanish Town to Montego Bay to Black River and back to Spanish Town.

What distance do you travel?

3143141121126262140140 + + = km

Unit 15Data Collection

Favourite Sports

a) How many students choose Basketball in Grade 8?

b) How many more choose Football in Grade 7 than is Grade 10?

c) In which Grade was Football not the most popular sport?

Cricket Football BasketballTrack and

Field

Grade 7 6 18 5 14

Grade 8 5 16 7 15

Grade 9 7 14 10 12

Grade 10 2 12 10 19

Grade 11 8 13 12 10

77

66

1010

Unit 15Data Collection

Pictograns

a) How many customers used the shop on Wednesday?

b) How many customers used the shop on Monday?

c) How many customers used the shop during the week?

3535

3535

5050

3030 5050 2525 5050 6565 255255+ + + + + =

Unit 15Data Collection

Bar Charts

The table below shows the number of chocolates sold in a school canteen during one week.

a)How many more chocolates were sold on Friday than on Tuesday?

b)What was the total number sold through the week?

c)What was the mean number of chocolates sold daily?

d)What is the probability that, on a random day, fewer than 50 chocolates were sold?

- =

+ + + + =

Day Mon Tues Wed Thurs Fri

No of chocolates 22 45 58 35 60

2222 4545 5858 3535 6060 220220

6060 4545 1515

???

??

?

The table below shows the number of chocolates sold in a school canteen during one week.

e)Complete the bar chart to represent the information above.

Day Mon Tues Wed Thurs Fri

No of chocolates 22 45 58 35 60