Bluebook SAT Test One-Variable Data: Distributions and Measures of Center and Spread 8

Question 1

A dataset of 6 values has a mean of 10 and a median of 9. If the largest value is removed, which is most likely?

Accepted Answer

Mean decreases; median stays the same or decreases slightly

Answer

Mean increases; median increases

Answer

Mean stays the same; median decreases

Answer

Both mean and median increase

Question 2

The standard deviation of {3, 6, 9, 12, 15} compared to {30, 60, 90, 120, 150} is:

Accepted Answer

10 times smaller for the first dataset

Answer

The same for both datasets

Answer

10 times larger for the first dataset

Answer

Cannot be compared

Question 3

A data set is: 14, 14, 16, 17, 19, 21, 22, 23, 25, 30. What is the IQR?

Accepted Answer

7

Answer

8

Answer

9

Answer

16

Question 4

A researcher collects income data from a neighborhood. She finds the mean income is $90,000 but the median is $55,000. A newcomer with an income of $1,000,000 moves in. This would most likely:

Accepted Answer

Increase the mean substantially but barely affect the median

Answer

Increase both mean and median significantly

Answer

Increase the median substantially but barely affect the mean

Answer

Have no effect on either the mean or the median

Question 5

A symmetric distribution has mean 50. The values 45, 50, and 55 each appear equally often. This distribution has standard deviation closest to:

Accepted Answer

5

Answer

0

Answer

10

Answer

50

Question 6

A histogram shows customer wait times in minutes: most customers wait 3–5 minutes, but a few wait over 20 minutes. The distribution is right-skewed. Which statement is correct?

Accepted Answer

The mean is greater than the median

Answer

The mean equals the median

Answer

The mean is less than the median

Answer

The median is greater than the mode

Question 7

The scores on a 10-point quiz for 5 students are: 6, 7, 8, 9, and x. If the mean is 8, what is x?

Accepted Answer

10

Answer

9

Answer

8

Answer

7