Bluebook SAT Test One-Variable Data: Distributions and Measures of Center and Spread 3

Question 1

The mode of the dataset {2, 3, 3, 5, 7, 7, 7, 9} is:

Accepted Answer

7

Answer

The mode is the value that appears most often; 7 appears three times, more than any other value.

Question 2

Two datasets each have 10 values and the same mean of 20. Dataset X has values all between 18 and 22, while Dataset Y has values ranging from 5 to 35. Which has the greater standard deviation?

Accepted Answer

Dataset Y

Answer

Dataset Y's values are much more spread out from the mean, resulting in a greater standard deviation.

Question 3

A box plot has whiskers extending from 10 to 90, with Q1=30 and Q3=70. A data point at 95 would be classified as:

Accepted Answer

A mild outlier

Answer

The IQR is 40, and 1.5 × 40 = 60, so the upper fence is Q3 + 60 = 130; 95 is outside the whisker (90) but below the fence, making it a mild outlier.

Question 4

A dataset of 9 values has a median of 15. A 10th value of 15 is added. What happens to the median?

Accepted Answer

The median remains 15

Answer

Adding 15 places it in the middle of the sorted dataset; the median of the 10-value dataset averages the 5th and 6th values, both near 15, keeping the median at 15.

Question 5

The histogram below shows the distribution of test scores in a class. The distribution is left-skewed (skewed toward lower values). Which is most likely true?

Accepted Answer

Mode > Median > Mean

Answer

In a left-skewed distribution, the long tail pulls the mean left, so Mode > Median > Mean.

Bluebook SAT Practice Test

Bluebook SAT Practice Test

Bluebook SAT Test One-Variable Data: Distributions and Measures of Center and Spread 3