STATISTICS QUIZ
2. 
is the:
A. rule of opposites
B. rule of complements
C. addition rule
D. commutative rule
4. If P(A) = P(A|B), then events A and B are said to be
A. independent
B. mutually exclusive
C. exhaustive
D. complementary
9. The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.
| x | ||||||
| P (X=x) | 0.20 | 0.25 | 0.20 | 0.15 | 0.10 | 0.10 |
What is the standard deviation of X?
A. 3.24
B. 2.0
C. 1.24
D. 1.58
11. The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.
| x | |||||||
| P (X=x) | 0.55 | 0.15 | 0.10 | 0.10 | 0.04 | 0.03 | 0.03 |
What is the expected value of X? Place your answer, rounded to two decimal places in the blank. For example, 4.56 would be a legitimate entry.
12. Suppose that the probability that a new medication will cause a bad side effect is 0.03. If this medication is given to 150 people, what is the probability that more than three of them will experience a bad side effect? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1776 would be a legitimate answer.
13. Find the mean of the distribution shown below.
| P(X) | 0.24 | 0.31 | 0.45 |
Round your answer to two decimal place as necessary. For example, 4.56 would be a legitimate entry.
Mean =
14. If 1.5% of the bolts made by an automotive factory are defective, what is the probability that in a shipment of 200 bolts, there are 6 defective bolts? Place your answer, rounded to four decimal places, in the blank.
15. An ice cream vendor sells three flavors: chocolate, strawberry, and vanilla. Forty five percent of the sales are chocolate, while 30% are strawberry, with the rest vanilla flavored. Sales are by the cone or the cup. The percentages of cones sales for chocolate, strawberry, and vanilla, are 75%, 60%, and 40%, respectively. For a randomly selected sale, define the following events:
= chocolate chosen
= strawberry chosen
= vanilla chosen
= ice cream on a cone
ice cream in a cup
Find the probability that the ice cream was sold on a cone and was chocolate flavor. Place your answer, rounded to 4 decimal places, in the blank. For exampe, 0.3456 would be a legitimate entry.
16. A restaurant menu has a price-fixed complete dinner that consists of an appetizer, entrée, beverage, and dessert. You have a choice of five appetizers, ten entrees, three beverages, and six desserts. How many possible complete dinners are possible? Place your answer, as a whole number—no decimal places—in the blank. For example 176 would be a legitimate entry
17. An ice cream vendor sells three flavors: chocolate, strawberry, and vanilla. Forty five percent of the sales are chocolate, while 30% are strawberry, with the rest vanilla flavored. Sales are by the cone or the cup. The percentages of cones sales for chocolate, strawberry, and vanilla, are 75%, 60%, and 40%, respectively. For a randomly selected sale, define the following events:
= chocolate chosen
= strawberry chosen
= vanilla chosen
= ice cream on a cone
ice cream in a cup
Find the probability that the ice cream was sold in a cup and was chocolate flavor. Place your answer, rounded to 4 decimal places, in the blank. For exampe, 0.3456 would be a legitimate entry.
18. An ice cream vendor sells three flavors: chocolate, strawberry, and vanilla. Forty five percent of the sales are chocolate, while 30% are strawberry, with the rest vanilla flavored. Sales are by the cone or the cup. The percentages of cones sales for chocolate, strawberry, and vanilla, are 75%, 60%, and 40%, respectively. For a randomly selected sale, define the following events:
= chocolate chosen
= strawberry chosen
= vanilla chosen
= ice cream on a cone
ice cream in a cup
Find the probability that the ice cream was sold in a cup. Place your answer, rounded to 4 decimal places, in the blank. For exampe, 0.3456 would be a legitimate entry.
19. True or False: When rolling two dice, the outcomes “doubles” and “totals 7” are mutually exclusive.
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20. The expected number of tails in 500 tosses of an unbiased coin is 200.
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