Quiz 2_MATH302
Question 1 of 20 1.0/ 1.0 Points
The staff at a small company includes: 4 secretaries, 20 technicians, 4 engineers, 2 executives, and 50
factory workers. If a person is selected at random, what is the probability that he or she is a factory
worker?
A. 1/4 B. 1/8 C. 5/8 D. 2/5
Answer Key: C
Question 2 of 20 1.0/ 1.0 Points
If two events are mutually exclusive, what is the probability that one or the other occurs?
Answer Key: C
Question 3 of 20 1.0/ 1.0 Points
If one tosses a coin enough times, the proportion of "heads" will approach 0.5. This is an example of:
Answer Key: A
Question 4 of 20 1.0/ 1.0 Points

If P(A) = P(A|B), then events A and B are said to be
A. independent
B. complementary
C. mutually exclusive
D. exhaustive
Answer Key: A
Question 5 of 20 1.0/ 1.0 Points
The number of ways to choose two representatives from a committee of 13 people is
A. 55
B. 78
C. 13!
D. 156
Answer Key: B
Question 6 of 20 1.0/ 1.0 Points
The binomial distribution can occur in which of the following situations? I. whenever we are interested in the number of events that occur over a given interval of time II. whenever we sample from a population with only two types of members III. whenever we perform a sequence of identical experiments, each of which has only two possible outcomes
Answer Key: C
Question 7 of 20 1.0/ 1.0 Points

A drug is reported to benefit 40% of the patients who take it. If 6 patients take the drug, what is the
probability that 4 or more patients will benefit?
A. 0.179B. 0.862 C. 0.667 D. 0.138
Answer Key: A
Question 8 of 20 1.0/ 1.0 Points
Suppose that 50 identical batteries are being tested. After 8 hours of continuous use, assume that a
given battery is still operating with a probability of 0.70 and has failed with a probability of 0.30.
What is the probability that between 25 and 30 batteries (inclusive) will last at least 8 hours?
Answer Key: B
Question 9 of 20 1.0/ 1.0 Points
Suppose that 50 identical batteries are being tested. After 8 hours of continuous use, assume that a
given battery is still operating with a probability of 0.70 and has failed with a probability of 0.30.
What is the probability that greater than 30 batteries will last at least 8 hours?
Answer Key: C
Question 10 of 20 1.0/ 1.0 Points

The probability distribution associated with the number of cartoons watched by Mrs. Kelly's first grade
class on Saturday morning is shown below.
X
P(x)
0
0.15
1
0.20
2
0.30
3
0.10
4
0.20
5
0.05
A. 1.46
B. 2.25
C. 1.89
D. 1.18
Answer Key: A
Question 11 of 20 1.0/ 1.0 Points

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