7-1 Mean, Median, Mode, and Range

7-2 Additional Data and Outliers

7-3 Choosing the Most Useful Measure

7-4 Analyzing Data Displays

7-5 Misleading Graphs

7-6 Populations and Samples

7-7 Selecting Samples

7-8 Identifying Sampling Errors and Bias

PreviewPreview

Lesson QuizzesLesson Quizzes

Lesson QuizUse the following data set: 18, 20, 56, 47, 30, 18, 21.

1. Find the range. 2. Find the mean.

3. Find the median. 4. Find the mode.

5. Bonnie ran a mile in 8 minutes, 8 minutes, 7

minutes, 9 minutes, and 8 minutes. What was

her mean time?

38 30

21 18

8 minutes

7-1 Mean, Median, Mode, and Range

Lesson QuizAt the college bookstore, your brother buys 6 textbooks at the following prices: $21, $58, $68, $125, $36, and $140.

1. Find the mean.

2. Find the median.

3. Find the mode.

4. Your brother signs up for an additional class,

and the textbook costs $225. Recalculate the

mean, including the extra book.

$63

$74.67

none

$96.14

7-2 Additional Data and Outliers

Lesson Quiz1. The top running speeds of six mammals are 15,

22, 30, 20, 26, and 37 miles per hour. What are the mean and median of this data set? Is one measure more useful than the other for describing the typical running speed of these mammals? Explain.

2. The price of a DVD at seven different stores is

given below. Should Ann use the mean, median,

or mode to convince a friend that the DVD is too

expensive? Explain. $20, $12, $13, $17, $14,

$12, $20

Mean: 25; median: 24; mean or median; there is no outlier.

Mean; it makes the price seem highest.

7-3 Choosing the Most Useful Measure

Lesson Quiz: Part I

Use the bar graph for Exercises 1 and 2 to answer each question.

1. What was the approximate maximum 24-hour precipitation for Virginia?

2. Emma claims that the maximum 24-hour precipitation for Florida is about 27 inches more than for Indiana. Is her claim valid? Explain.

about 27 in.

yes

7-4 Analyzing Data Displays

Lesson Quiz: Part II

Use the circle graph for Exercises 3 and 4 to answer each question.

3. In 2005, what percent of overseas visitors came from Europe or Asia?

4. Jay claims that in 2005 less than 1/4 of overseas visitors came from Asia. Is his claim valid?

77%

no

7-4 Analyzing Data Displays

Lesson Quiz: Part IIl

Use the line graph for Exercises 5 and 6 to answer each question.

5. What was the approximate average cost of a major league baseball ticket in 1995?

6. Kelsey claims that the average price of a major league baseball ticket increased by more than $10 between 1991 and 2005. Is her claim valid?

about $11

yes

7-4 Analyzing Data Displays

Lesson QuizExplain why each graph could be misleading and why.

The vertical scale does not start at 0, so it looks like sales revenues were small.

The scale does not start at 0, so it looks like fewer people like each type of animal.

1. 2.

7-5 Misleading Graphs

Lesson Quiz: Part I

1. Explain whether it makes sense to use a sample if you want to know the average length of dolphins at the aquarium.No; the population is small.

7-6 Populations and Samples

Lesson Quiz: Part ll2. About 22% of Americans go to the beach each

year. Amanda surveys a random sample of people from two towns. Compare the samples with the national percent.

The percent of people from Town A who visited the beach (70%) is greater than the national percent. The percent of people from Town B (20%) is close to the national percent.

Beach Visits in the Past Year

Sample Yes No

Town A 56 24

Town B 16 64

7-6 Populations and Samples

3. A doctor has 600 patients. She estimates that 175 of them exercise nearly every day. She surveys a random sample of 40 patients and finds that 12 exercise nearly every day. Determine whether the doctor’s estimate is likely to be accurate. Explain.

Lesson Quiz: Part IIl

Yes; based on the sample, you can predict that 180 patients exercise nearly every day.

7-6 Populations and Samples

An eye doctor wants to know how many of her patients work at a computer. Identify each type of sampling method.

1. The doctor surveys the patients in the waiting room one morning.

2. The doctor places cards in the waiting room.

3. The doctor chooses every 50th name from a database of her patients.

Lesson Quiz

convenience sample

self-selected sample

systematic sample

7-7 Selecting Samples

Lesson Quiz: Part I

1. Determine whether the sample may be biased. Explain. A dentist chooses 30 patients to survey by selecting names at random from his database.

2. Determine whether the survey question may be biased. Explain. Given its enormous cost, do you support a space mission to the moon?

The sample is not biased. It is a random sample.

Biased; the words enormous cost lead people to answer no.

7-8 Identifying Sampling Errors and Bias

3. Vietta conducts a survey to find out whether students would like a salad bar in the cafeteria. Determine whether Vietta’s claim is valid. Explain.

Sample: 50 names chosen at random from the school’s enrollment list

Question: Many students have said they would like a salad bar; do you agree?

Results:

Claim: Most students want a salad bar added to the cafeteria.

Lesson Quiz: Part II

No; the question is biased. It leads students to answer yes.

Survey: Salad Bar

Yes 76%

No 20%

Don’t know 4%

7-8 Identifying Sampling Errors and Bias