exam one

The probability Pete will catch fish when he goes fishing is .8. Pete is going fishing 3 days next week. Refer to Exhibit 5-10. The probability that Pete will catch fish on exactly 1 day is _____. What is the random variable in this experiment?

.096 the number of days out of 3 that Pete catches fish

If P(A) = .75, P(A ∪ B) = .86, and P(A ∩ B) = .56, then P(B) =

.67

If A and B are mutually exclusive events with P(A) = .3 and P(B) = .5, then P(A ∪ B) =

.8

The student body of a large university consists of 59% female students. A random sample of 8 students is selected. Refer to Exhibit 5-8a. What is the probability that among the students in the sample exactly 2 are female?

0.046298

x is a random variable with the probability function: f(x) = x/6 for x = 1, 2, or 3. The expected value of x is _____.

2.333

The random variable x is the number of occurrences of an event over an interval of 10 minutes. It can be assumed the probability of an occurrence is the same in any two time periods of an equal length. It is known that the mean number of occurrences in 10 minutes is 5.3. Refer to Exhibit 5-11. The appropriate probability distribution for the random variable is _____.

discrete

The 50th percentile is the _____.

median

Which of the following symbols represents the size of a sample?

n

The descriptive measure of dispersion that is based on the concept of a deviation about the mean is _____

neither the range nor the interquartile range

A(n) _____ is an unusually small or unusually large data value.

outlier

Which of the following is NOT a measure of location?

variance

The number of customers at Winkies Donuts between 8:00 A.M. and 9:00 A.M. is believed to follow a Poisson distribution with a mean of 3 customers per minute. What is the probability of exactly 8 customers arriving during a 3 minute interval?

0.13176

Consider a Poisson probability distribution in a process with an average of 2 flaws every 100 feet. Find the probability of 4 or 5 flaws in 120 feet.

0.1856

A method of assigning probabilities based upon judgment is referred to as the _____.

None of the answers is correct.

If A and B are independent events with P(A) = .38 and P(B) = .55, then P(A | B) =

None of the answers is correct.

If A and B are mutually exclusive, then _____.

P(A B) = 0

If A and B are independent events with P(A) = 0.1 and P(B) = .4, then _____.

P(A ∩ B) = .04

Which of the following is a characteristic of a binomial experiment?

The trials are independent.

Which of the following statements about a discrete random variable and its probability distribution is true?

Values of f(x) must be greater than or equal to zero.