Exam 6: Continuous Random Variables

An apple juice producer buys all his apples from a conglomerate of apple growers in one northwestern state.The amount of juice squeezed from each of these apples is approximately normally distributed with a mean of 2.25 ounces and a standard deviation of 0.15 ounce.Between what two values (in ounces)symmetrically distributed around the population mean will 80 percent of the apples fall?

The time it takes a woman to travel from her apartment to the bus station follows a uniform distribution over the interval from 20 to 30 minutes.If she leaves home at 9:05 a.m. ,what is the probability that she will get to the station between 9:25 and 9:30 a.m.?

The weight of a product is normally distributed with a mean of four ounces and a variance of .25 squared ounces.What is the probability that a randomly selected unit from a recently manufactured batch weighs more than 3.75 ounces?

While conducting experiments,a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m.What is the expected value of the water depth?

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of 0.2 inches.What is the probability that a sheet selected at random will be less than 29.75 inches long?

The standard deviation of a standard normal distribution is always equal to 1.

An aptitude test has a mean score of 80 and a standard deviation of 5.The population of scores is normally distributed.What raw score corresponds to the 70^th percentile?

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes.What is the probability that the service time is between 2 and 4 minutes?

The weight of a product is normally distributed with a mean of four ounces and a variance of .25 squared ounces.What is the probability that a randomly selected unit from a recently manufactured batch weighs more than 5 ounces?

The flying time of a drone airplane has a normal distribution with mean 4.76 hours and standard deviation of .04 hours.What is the probability that the drone will fly more than 4.80 hours?

Suppose that the waiting time for a license plate renewal at a local office of a state motor vehicle department has been found to be normally distributed with a mean of 30 minutes and a standard deviation of 8 minutes.What is the probability that a randomly selected individual will have a waiting time of at least 10 minutes?

The first step to constructing a normal probability plot is:

While conducting experiments,a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m.What is the probability that a randomly selected depth is between 2.25 m and 5.00 m?

A study shows that employees that begin their workday at 9:00 a.m.vary their times of arrival uniformly from 8:40 a.m.to 9:30 a.m.The probability that a randomly chosen employee reports to work between 9:00 and 9:10 is:

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of 0.2 inches.What is the probability that a sheet selected at random from the population is between 29.75 and 30.5 inches long?

If the random variable X has a mean of µ and a standard deviation σ,then (X - µ)/σ has a mean and standard deviation respectively:

Suppose that the waiting time for a license plate renewal at a local office of a state motor vehicle department has been found to be normally distributed with a mean of 30 minutes and a standard deviation of 8 minutes.What is the probability that a randomly selected individual will have a waiting time of no more than 22 minutes?

Which of the following statements is not a property of the normal probability distribution?

What is the probability that a standard normal random variable will be between 0.3 and 3.2?

A probability distribution that describes the time or space between successive occurrences of an event is a(n)____________ probability distribution.