Exam 5: Discrete Probability Distributions

According to geologists, the San Francisco Bay Area experiences five earthquakes with a magnitude of 6.5 or greater every 100 years. What is the probability that more than two earthquakes with a magnitude of 6.5 or greater will strike the San Francisco Bay Area in the next 40 years?

It is known that 10% of the calculators shipped from a particular factory are defective. What is the probability that no more than one in a random sample of four calculators is defective?

According to a study by the Centers for Disease Control and Prevention, about 33% of U.S. births are Caesarean deliveries. Suppose seven expectant mothers are randomly selected. What is the standard deviation of the number of mothers who will have a Caesarean delivery?

Thirty percent of the CFA candidates have a degree in economics. A random sample of three CFA candidates is selected. What is the probability that at least one of them has a degree in economics?

An urn contains 12 balls, five of which are red. The selection of a red ball is desired and is therefore considered to be a success. If a person draws three balls from the urn, what is the probability of two successes?

Consider the following probability distribution. The variance is ________.

Which of the following can be represented by a continuous random variable?

On a particular production line, the likelihood that a light bulb is defective is 5%. Ten light bulbs are randomly selected. What are the mean and variance of the number of defective bulbs?

According to the Department of Transportation, 27% of domestic flights were delayed in the last year at JFK airport. Five flights are randomly selected at JFK. What is the probability that all five flights are on time?

A bank manager estimates that an average of two customers enters the tellers' queue every five minutes. Assume that the number of customers that enters the tellers' queue is Poisson distributed. What is the probability that at least two customers enter the queue in a randomly selected five-minute period?

Consider the following discrete probability distribution. What is the probability that X is less than 5?

Assume that the mean success rate of a Poisson process is six successes per hour. A) Find the expected number of successes in a 40-minute period. B) Find the expected number of successes in a three-hour period. C) Find the probability of at least two successes in a 30-minute period.

Chauncey Billups, a current shooting guard for the Los Angeles Clippers, has a career free-throw percentage of 89.4%. Suppose he shoots six free throws in tonight's game. What is the standard deviation of the number of free throws that Billups will make?

The following table shows the number of students who did not attend statistics class over the 35 class meetings last semester. What is the expected number of absent students per class for the next semester?

According to the Department of Transportation, 27% of domestic flights were delayed in the last year at JFK airport. Five flights are randomly selected at JFK. What is the probability that all five flights are delayed?

Given two random variables X and Y, the expected value of their sum, E (X + Y), is equal to the sum of their individual expected values, E (X) and E (Y).

The Excel's function HYPERGEOM.DIST can be used to solve hypergeometric probabilities.

The foreclosure crisis has been particularly devastating in housing markets in much of the south and west United States, but even when analysis is restricted to relatively strong housing markets the numbers are staggering. For example, in 2017 an average of three residential properties were auctioned off each weekday in the city of Boston, up from an average of one per week in 2011. What is the probability that exactly 10 foreclosure auctions occurred during a randomly selected five-day week in 2017 in Boston?