Math Math Statistics and Data Analysis 4

Question 1

A dataset has values 12, 15, 15, 18, 20, 22, 50. Which measure of center best represents this data?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Answer

Range

Question 2

In a normal distribution, approximately what percentage of data falls within two standard deviations of the mean?

Accepted Answer

95%

Answer

68%

Answer

90%

Answer

99.7%

Question 3

A survey finds a correlation of r = -0.85 between hours of TV watched and GPA. What does this indicate?

Accepted Answer

There is a strong negative association between the variables

Answer

TV watching causes lower GPA

Answer

There is a weak negative association

Answer

GPA causes less TV watching

Question 4

Which sampling method divides the population into groups and randomly selects entire groups?

Accepted Answer

Cluster sampling

Answer

Stratified sampling

Answer

Systematic sampling

Answer

Simple random sampling

Question 5

A box plot shows Q1 = 30, Q2 = 45, Q3 = 60. What is the interquartile range (IQR)?

Accepted Answer

30

Answer

15

Answer

45

Answer

75

Question 6

A data set has a mean of 50 and standard deviation of 10. What is the z-score for a value of 35?

Accepted Answer

-1.5

Answer

-0.5

Answer

1.5

Answer

0.5

Question 7

Which of the following is an example of qualitative (categorical) data?

Accepted Answer

Favorite genre of music

Answer

Heights of students in inches

Answer

Number of absences per student

Answer

Test scores out of 100