Exam 4: Discrete Random Variables

Classify the following random variable according to whether it is discrete or continuous. The height of a player on a basketball team

Calculate the mean for the discrete probability distribution shown here. X 2 4 6 10 P(X) .2 .3 .3 .2

Solve the problem. Round to four decimal places. -A recent study suggested that 70% of all eligible voters will vote in the next presidential election. Suppose 20 eligible voters were randomly selected from the population of all eligible voters. Use a Binomial probability table to find the probability that more than 10 but fewer than 16 of the 20 Eligible voters sampled will vote in the next presidential election.

A bottle contains 16 ounces of water. The variable x represents the volume, in ounces, of water remaining in the bottle after the first drink is taken. What are the natural bounds for the values of x? Is x discrete or continuous? Explain.

A recent survey found that 70% of all adults over 50 wear glasses for driving. In a random sample of 70 adults over 50, what is the mean and standard deviation of the number who wear glasses? Round to the nearest hundredth when necessary.

Consider the given discrete probability distribution. Find the probability that x exceeds 4.

A discrete random variable x can assume five possible values: 2, 3, 5, 8, 10. Its probability distribution is shown below. Find the mean of the distribution. 2 3 5 8 10 () 0.10 0.20 0.30 0.30 0.10

The expected value of a discrete random variable must be one of the values in which the random variable can result.

About 40% of the general population donate time and energy to community projects. Suppose 15 people have been randomly selected from a community and each asked whether he or she donates time and energy to community projects. Let x be the number who donate time and energy to community projects. Use a binomial probability table to find the probability that more than five of the 15 donate time and energy to community projects.

Suppose the number of babies born each hour at a hospital follows a Poisson distribution with a mean of 4. Find the probability that exactly seven babies are born during a randomly selected hour.

Suppose a man has ordered twelve 1-gallon paint cans of a particular color (lilac)from the local paint store in order to paint his motherʹs house. Unknown to the man, three of these cans contains An incorrect mix of paint. For this weekendʹs big project, the man randomly selects four of these 1-gallon cans to paint his motherʹs living room. Let x = the number of the paint cans selected that Are defective. Unknown to the man, x follows a hypergeometric distribution. Find the mean of this Distribution.

The school newspaper surveyed 100 commuter students and asked two questions. First, students were asked how many courses they were currently enrolled in. Second, the commuter students Were asked to estimate how long it took them to drive to campus. Considering these two variables, Number of courses would best be considered a _________ variable and drive time would be Considered a _________ variable.

Which binomial probability is represented on the screen below?

Classify the following random variable according to whether it is discrete or continuous. The number of goals scored in a soccer game