Bluebook SAT Test One-Variable Data: Distributions and Measures of Center and Spread 7

Question 1

Which of the following changes would NOT affect the median of a dataset?

Accepted Answer

Changing the largest value to an even larger number

Answer

Removing the smallest value

Answer

Adding a value equal to the current median

Answer

Changing the smallest value to a still-smaller number

Question 2

A dataset has values 10, 20, 30, 40, and 50. The mean is 30 and the range is 40. If every value is increased by 5, the new mean and range are:

Accepted Answer

Mean=35, Range=40

Answer

Mean=30, Range=40

Answer

Mean=35, Range=45

Answer

Mean=30, Range=45

Question 3

A frequency histogram shows test scores. The bars have heights: 50-59: 2 students, 60-69: 4 students, 70-79: 8 students, 80-89: 6 students, 90-99: 2 students. What is the modal class?

Accepted Answer

70-79

Answer

60-69

Answer

80-89

Answer

90-99

Question 4

The mean of a dataset is 25 and the standard deviation is 5. If a value of 40 is added to the dataset, what happens?

Accepted Answer

Mean increases; standard deviation increases

Answer

Mean decreases; standard deviation decreases

Answer

Mean increases; standard deviation decreases

Answer

Mean stays the same; standard deviation increases

Question 5

The data set {5, 8, 10, 12, 15} has a mean of 10. Which value, if replaced by 30, would cause the greatest increase in standard deviation?

Accepted Answer

10

Answer

5

Answer

8

Answer

15

Question 6

A box plot shows: Min=5, Q1=15, Median=22, Q3=30, Max=42. Which interval contains approximately 50% of the data?

Accepted Answer

15 to 30

Answer

5 to 42

Answer

5 to 22

Answer

22 to 42

Question 7

A teacher calculates class mean scores: Quiz 1 mean = 70, Quiz 2 mean = 80. The class took both quizzes with 20 students each. What is the mean score across both quizzes combined?

Accepted Answer

75

Answer

150

Answer

70

Answer

80