Math Math Statistics and Data Analysis 5

Question 1

A probability experiment has P(A) = 0.4 and P(B) = 0.3, with A and B independent. What is P(A and B)?

Accepted Answer

0.12

Answer

0.70

Answer

0.58

Answer

0.10

Question 2

A stem-and-leaf plot shows stems 1, 2, 3 with leaves 2|3, 1|5|8, 0|4. What is the median?

Accepted Answer

25

Answer

21

Answer

28

Answer

30

Question 3

Which type of graph is most appropriate for showing the distribution of a single quantitative variable?

Accepted Answer

Histogram

Answer

Bar chart

Answer

Pie chart

Answer

Line graph

Question 4

In a scatterplot, the points cluster tightly around a line with positive slope. This indicates:

Accepted Answer

A strong positive correlation

Answer

A strong negative correlation

Answer

A weak positive correlation

Answer

No correlation

Question 5

A class of 30 students has a mean score of 80. If 10 more students with a mean of 70 join, what is the new overall mean?

Accepted Answer

77

Answer

75

Answer

76.5

Answer

78

Question 6

Which of the following would most likely cause voluntary response bias in a survey?

Accepted Answer

Asking only people who choose to call in to a radio show

Answer

Randomly selecting participants from a phone book

Answer

Using a stratified random sample

Answer

Surveying every 10th customer entering a store

Question 7

A data set has values 5, 7, 7, 8, 10, 12. What is the variance?

Accepted Answer

5.0

Answer

2.5

Answer

4.9

Answer

6.25