Exam 5: Discrete Probability Distributions

The average number of calls received by a switchboard in a 30-minute period is 15. a.Define the random variable in words for this experiment. b.What is the probability that between 10:00 and 10:30 the switchboard will receive exactly 10 calls? c.What is the probability that between 10:00 and 10:30 the switchboard will receive more than 9 calls but fewer than 15 calls? d.What is the probability that between 10:00 and 10:30 the switchboard will receive fewer than 7 calls?

For the following probability distribution: a.Determine E(x). b.Determine the variance and the standard deviation.

A continuous random variable may assume

The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution. The mean and the standard deviation for the number of electrical outages (respectively) are

Exhibit 5-6 Probability Distribution -Refer to Exhibit 5-6. The variance of x equals

When using Excel's BINOM.DIST function, one should choose TRUE for the fourth input if

Only 0.02% of credit card holders of a company report the loss or theft of their credit cards each month. The company has 15,000 credit cards in the city of Memphis. What is the probability that during the next month in the city of Memphis a.no one reports the loss or theft of their credit cards? b.every credit card is lost or stolen? c.six people report the loss or theft of their cards? d.at least nine people report the loss or theft of their cards? e.Determine the expected number of reported lost or stolen credit cards. f. Determine the standard deviation for the number of reported lost or stolen cards.

When a particular machine is functioning properly, 80% of the items produced are non-defective. If three items are examined, what is the probability that one is defective? Use the binomial probability function to answer this question.

During lunchtime, customers arrive at Bob's Drugs according to a Poisson distribution with  = 4 per minute. a. During a one minute interval, determine the following probabilities: (1) no arrivals; (2) one arrival; (3) two arrivals; and, (4) three or more arrivals. b. What is the probability of two arrivals in a two-minute period?

The Poisson probability distribution is used with

Exhibit 5-10 The probability that Pete will catch fish on a particular day when he goes fishing is 0.8. Pete is going fishing 3 days next week. -Refer to Exhibit 5-10. The expected number of days Pete will catch fish is

The probability distribution for the rate of return on an investment is a.What is the probability that the rate of return will be at least 10%? b.What is the expected rate of return? c.What is the variance of the rate of return?

Which of the following is not a characteristic of an experiment where the binomial probability distribution is applicable?

Excel's HYPGEOM.DIST function has how many inputs?

Exhibit 5-8 The student body of a large university consists of 60% female students. A random sample of 8 students is selected. -Refer to Exhibit 5-8. What is the probability that among the students in the sample at least 7 are female?

A measure of the average value of a random variable is called a(n)

Exhibit 5-3 The probability distribution for the number of goals the Lions soccer team makes per game is given below. -Refer to Exhibit 5-3. The expected number of goals per game is

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

The expected value for a binomial probability distribution is

Which of the following is(are) required condition(s) for a discrete probability function?