Question 1

Select one answer.

10 points

Here is the 5-number summary for a group of 100 runners in a 5-kilometer race. The variable is the time to complete the race:

Five-number summary:

Minimum: 15 minutes

Q1: 27 minutes

Median: 31 minutes

Q3: 32 minutes

Maximum: 50 minutes

Given the five-number summary above, which of the following statements about the distribution is most accurate?

- Most people finished between 15 and 50 minutes, but some people took a little longer.
- There were more runners in the 2nd quartile (Q1 = 27 mins to Median = 31 mins) than in the 3rd quartile (Median = 31 mins to Q3 = 32 mins).
- At least 25 runners had times ranging from 31 minutes to 32 minutes.

Question 2

Select one answer.

10 points

Here again is the 5-number summary for a group of 100 runners in a 5-kilometer race. The variable is the time to complete the race.

Five-number summary:

Minimum: 15 minutes

Q1: 27 minutes

Median: 31 minutes

Q3: 32 minutes

Maximum: 50 minutes

Are there any outliers in the runners’ finish times by the 1.5*IQR definition?

- The slowest runner is an outlier, but the fastest runner is not an outlier.
- The fastest runner is an outlier, but the slowest runner is not an outlier.
- Both the slowest and the fastest runners are outliers.
- There are no outliers.

Question 3

Select one answer.

10 points

This histogram shows the distribution of exam scores for a class of 33 students.Which of the following is the most reasonable estimate for the median?

- 50
- 75
- 85

Question 4

Select one answer.

10 points

This histogram shows the distribution of exam scores for a class of 33 students.Which of the following is the most reasonable estimate of the IQR (interquartile range)?

- 25
- 50
- 75
- 0 to 100

Question 5

Select one answer.

10 points

Which of the following boxplots represents the data displayed in the above histogram (Question 4)?

- Boxplot A
- Boxplot B
- Boxplot C
- Boxplot D

Question 6

Select one answer.

10 points

In a survey, students at two community colleges students estimated the hours they spend on Facebook each week.Tell whether the following statement provides a valid conclusion that can be drawn from the boxplots.

The medians are close; they differ by about half an hour. This suggests that the typical student at each college spends about the same amount of time on Facebook each week.

- Valid
- Invalid

Question 7

Select one answer.

10 points

In a survey, students at two community colleges students estimated the hours they spend on Facebook each week.Tell whether the following statement provides a valid conclusion that can be drawn from the boxplots.

If we use Q1 and Q3 to define a typical range of values, the typical students at College B are on Facebook 7.5 to 9 hours a week.

- Valid
- Invalid

Question 8

Select one answer.

10 points

In a survey, students at two community colleges students estimated the hours they spend on Facebook each week.We have learned different measures of variability. Different measures might lead to different conclusions. Determine if the following statement is a valid conclusion for this data.

If we use range as a measure of variability, then College A has more variability.

- Valid
- Invalid

Question 9

Select one answer.

10 points

In a survey, students at two community colleges students estimated the hours they spend on Facebook each week.Tell whether the following statement provides a valid conclusion that can be drawn from the boxplots.

There is less variability in data from College A because the IQR is smaller.

- Valid
- Invalid

Question 10

Select one answer.

10 points

Which boxplot has the 5-number summary: min = 0, Q1 = 0.5, Q2 = 2, Q3 = 3, Max = 6?

- Boxplot A
- Boxplot B
- Boxplot C