Series of Probability Questions

1. A survey of 120 people found that 20 of them use shampoos A and C, 10 use A and B but not C, 15 use all three, 30 use only C, 35 use B but not C, 25 use B and C, and 10 use none of the three. What percentage of the people surveyed use only A. (Hint: fill in Venn diagram from the inside out - from the intersection of all three.)
a. 10 b. 15 c. 20 d. 25

2. A pair of dice is rolled. What is the probability the numbers on the two dice differ by 2 (either +2 or -2)?
a. 6/36 b. 8/36 c. 9/36 d. 10/36

3. A dog must go through one of 3 doors A, B, or C, to get to his food. If the probability of going through B is twice the probability of going through C, and the probability of going through A is three times the probability of going through B, what is the probability the dog will go through door B? (Hint: let x be the probability of going through C and the other probabilities in terms of x.)
a. 2/6 b. 1/6 c. 1/9 d. 2/9

4. Consider the data set S ={4,5,6,6,7,8,9,10,17}. The mean and median (in that order) are
a.) 8 and 7 b. 6 and 7 c. 8 and 6 d. 7.6 and 6.5

5. Which of the following are least affected if an extreme outlier were to be added to a set of data?
a. standard deviation b. median c. mean d. correlation

6. Which of the following is an advantage of using a bar graph instead of a pie chart to visualize data for a categorical variable?
a. bar graphs are better for displaying categorical variables with a lot of categories
b. it is easier to make comparisons between categories using bar graphs
c. more of the categories can be included in a bar graph
d. all of the above

7. If A and B are correlated, this means only that
a. there is linear association between A and B
b. A causes B
c. B causes A
d. C causes A and B

8. A set of data has a median that is much larger than the mean. Which of the following statements is most consistent with this information?
a. a histogram of the data is symmetric
b. a histogram of the data is extends to the right (bigger numbers)
c. a histogram of the data extends to the left (smaller numbers)
d. none of these

9. A committee of 4 is be selected from a group of 5 men and 6 women How many committees are possible?
a. 114 b. 5040 c. 330 d. 120

10. If 28% of the households in a certain neighborhood subscribe to The New Yorker, 36 percent to The Midnight Star, and 3 percent to both. What percent read exactly one of these publications?
a. 64% b. 58% c. 61% d. 39%