College Math Placement Test Statistics 5

Question 1

A data set has mean 50 and standard deviation 10. A value of 70 has a z-score of:

Accepted Answer

2

Answer

1

Answer

−2

Answer

7

Question 2

If events A and B are independent and P(A) = 0.4, P(B) = 0.5, what is P(A and B)?

Accepted Answer

0.2

Answer

0.9

Answer

0.1

Answer

0.45

Question 3

A histogram with bars of roughly equal height suggests the distribution is:

Accepted Answer

Uniform

Answer

Normal

Answer

Skewed right

Answer

Bimodal

Question 4

The stem-and-leaf plot shows stems 1, 2, 3 with leaves 2 3 | 1 4 6 | 0 5. What is the median?

Accepted Answer

24

Answer

21

Answer

30

Answer

26

Question 5

A confidence interval is reported as (48, 56). What is the margin of error?

Accepted Answer

4

Answer

8

Answer

52

Answer

2

Question 6

Which of the following best describes an observational study?

Accepted Answer

Researchers collect data without manipulating any variables

Answer

Researchers assign subjects to treatment and control groups

Answer

Researchers manipulate variables to determine cause and effect

Answer

Researchers use a placebo to control for bias

Question 7

Which measure best describes the center of a data set that contains an extreme outlier?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Answer

Standard deviation