Exam 5: Discrete Probability Distributions

According to the Mortgage Bankers Association,8% of U.S.mortgages were delinquent in 2011.A delinquent mortgage is one that has missed at least one payment but has not yet gone to foreclosure.A random sample of eight mortgages was selected.What is the probability that exactly one of these mortgages is delinquent?

There are currently 18 pit bulls at the pound.Of the 18 pit bulls,four have attacked another dog in the last year.Joe,a member of the staff,randomly selects six of the pit bulls for his group.What is the probability that exactly one of the pit bulls in Joe's group attacked another dog last year?

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 no earthquakes with a magnitude of 6.5 or greater strike the San Francisco Bay Area in the next 40 years?

What is a characteristic of the mass function of a discrete random variable X?

A probability distribution of a continuous random variable X gives the probability that X takes on a particular value x,P(X = x).

Consider the following cumulative distribution function for the discrete random variable. What is the probability that X equals 2?

Consider the following cumulative distribution function for the discrete random variable X. What is the probability that X is greater than 2?

The number of syntactic errors found in a program code would best be described using a Poisson probability distribution.

Cars arrive randomly at a tollbooth at a rate of 20 cars per 10 minutes during rush hour.What is the probability that exactly five cars will arrive over a five-minute interval during rush hour?

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

On a particular production line,the likelihood that a light bulb is defective is 5%.Ten light bulbs are randomly selected.What is the probability that none of the light bulbs will be defective?

The variance of a random variable X provides us with a measure of central location of the distribution of X.

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?

Studies have shown that bats can consume an average of 10 mosquitoes per minute.What is the probability that a bat consumes four mosquitoes in a 30-second interval?

It is known that 10% of the calculators shipped from a particular factory are defective.What is the probability that none in a random sample of four calculators is defective?

The following table shows the number of students who did not attend statistics class over the 30 class meetings last semester. What is the probability that there will be more than one student absent in class today?

A construction company found that on average its workers get into four car accidents per week. a.What is the probability of exactly six car accidents in a random week? b.What is the probability that there are fewer than two car accidents in a random week? c.What is the probability that there are exactly eight car accidents over the course of three weeks?

A consumer who is risk averse is best characterized as _____________________________________________________.

A random variable is a function that assigns numerical values to the outcomes of a random experiment.

An urn contains 12 balls,five of which are red.Selection of a red ball is desired and is therefore considered to be a success.If three balls are selected,what is the expected value of the distribution of the number of selected red balls?