Bluebook SAT Test One-Variable Data: Distributions and Measures of Center and Spread 11

Question 1

Which of the following correctly describes a right-skewed (positively skewed) distribution?

Accepted Answer

The tail extends to the right and the mean is greater than the median.

Answer

In a right-skewed distribution, the longer tail is on the right, which pulls the mean above the median.

Question 2

A data set has 7 values with a median of 18. A new value of 5 is added to the dataset, making it 8 values total. What is the new median?

Accepted Answer

It cannot be determined without knowing all values.

Answer

Without knowing the specific values around the median, we cannot calculate the exact new median; we only know the original median was 18 and a smaller value was added.

Question 3

The standard deviation of a dataset is 0. Which of the following must be true?

Accepted Answer

All values in the dataset are equal.

Answer

A standard deviation of 0 means there is no variation; every value in the dataset must be identical to the mean.

Question 4

A dataset of 6 values: 4, 9, 11, x, 18, 22 is sorted in ascending order and has a median of 13. What is the value of x?

Accepted Answer

15

Answer

With 6 values, the median is the average of the 3rd and 4th values: (11 + x) ÷ 2 = 13, so 11 + x = 26, giving x = 15.

Question 5

A dataset has values 6, 9, 12, 15, 18. If each value is decreased by 3, which of the following changes?

Accepted Answer

The mean

Answer

Subtracting a constant from every value shifts the mean down by that constant but does not change the range or standard deviation, since those measure spread.

Bluebook SAT Practice Test

Bluebook SAT Practice Test

Bluebook SAT Test One-Variable Data: Distributions and Measures of Center and Spread 11