Exam 5: Continuous Random Variables

The lifetime of a stereo component is exponentially distributed with mean 1,000 days. What is the probability that the lifetime: -Exceeds 1,000 days?

The _____________ distribution would most likely be used to describe the distribution of time between arrivals of customers at the grocery store.

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: -What is the probability that a standard normal random variable will be between -2 and 2?

The yearly number of dental claims for the employees of the local shoe manufacturing company is normally distributed with a mean of 105 and a standard deviation of 35.What is the yearly number at which 35% of the employees fall at or below?

A study shows that employees that begin their work day 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:

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20. What percentage of the time will the number of boxes received weekly be -Between 180 and 210

Find z when the area to the left of z is .6700

The life of a light bulb is exponentially distributed with a mean of 1,000 hours. What is the probability that the bulb will last: -Less than 800 hours?

Suppose the daily change in price of a stock is normally distributed with mean = .20 and standard deviation = .30.What price change is associated with the 25^th percentile?

What is the probability that a randomly selected cable repair visit falls within 2 standard deviations of the mean?

The price of an energy sports drink is normally distributed with an average of $2.25 and a standard deviation of $0.15 across store outlets. -What is the probability that a randomly selected drink will cost between $2.00 and $2.50?

Suppose that the waiting time for a pizza to be delivered to an individual's residence 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 -No more than 22 minutes

The average distance between store outlets in a chain of stores in a large metropolitan city is 50km and has a standard deviation of 5km. What is the probability of finding a store: -No less than 55km away?

A normal distribution with mean zero and a standard deviation one is called the _____ normal distribution.

If the scores on an aptitude test are normally distributed with mean 500 and standard deviation 100,what proportion of the test scores are less than 585?

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. -Find the probability that a household spent less than $5.00

The average distance between store outlets in a chain of stores in a large metropolitan city is 50km and has a standard deviation of 5km. What is the probability of finding a store: -Between 50 km and 60 km?

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

Suppose the distribution of personality test scores is normally distributed with a mean of 15 and a variance of 25. -What percentage of the population scores greater than 15?

The mean life of pair of shoes is 40 months with a standard deviation of 8 months.If the life of the shoes is normally distributed,how many pairs of shoes out of one million will need replacement before 36 months?