A.) A telephone manufacturer finds that the life spans of its telephones are normally distributed, with...

A.) A telephone manufacturer finds that the life spans of its telephones are normally distributed, with a mean of 6.7 years and a standard deviation of 0.5 year. (Round your answers to three decimal places.)

What percent of its telephones will last at least 7.25 years?

What percent of its telephones will last between 5.8 years and 6.8 years?

What percent of its telephones will last less than 6.9 years?

B.) The amount of time customers spend waiting in line at the ticket counter of an amusement park is normally distributed, with a mean of 6.5 min and a standard deviation of 1 min.

Find the z-score for the following data value 8 min.

Find the probability that a customer will wait less than 8 minutes. (Round your answer to three decimal places.)

Find the z-score for the following data value 6 min.

Find the probability that a customer will wait less than 6 minutes. (Round your answer to three decimal places.)

Solutions

Expert Solution

thank you.

orchestra answered 1 year ago

Next > < Previous

Related Solutions

tire manufacturer claims that the life span of its tires is 60,000 miles. Assume the life spans of the tire are normally distributed.

tire manufacturer claims that the life span of its tires is 60,000 miles. Assume the life spans of the tire are normally distributed. You selected 25 tires at random and tested them. The mean life span of the sample is 58,800 miles. The tires had a sample standard deviation, s = 600. Use the .10 level of significance. Which distribution would be indicated? Explain why you chose that distribution. Construct a confidence interval for the mean using the above data....

According to actuarial tables, life spans in the United States are approximately normally distributed with a...

According to actuarial tables, life spans in the United States are approximately normally distributed with a mean of about 75 years and a standard deviation of about 16 years. 1) Find the probability that a randomly selected person lives between 60 less than 90 years. 2) Find the probability that a randomly selected person lives less than 50 years or more than 100 years. 3) Find the probability that a randomly selected person lives exactly 75 years. 4) What age...

A manufacturer of high intensity lamps finds that the useful life of the lamps is normally...

A manufacturer of high intensity lamps finds that the useful life of the lamps is normally distributed with population mean μ = 70 months and population standard deviation s = 12 months. A sample size n = 16 is taken. What is the probability that the sample mean is greater than 75 months?

A tire company finds the lifespan for one brand of its tires is normally distributed with...

A tire company finds the lifespan for one brand of its tires is normally distributed with a mean of 48,400 miles and a standard deviation of 5000 miles. If the manufacturer is willing to replace no more than 10% of the tires, what should be the approximate number of miles for a warranty? What is the probability that a tire will last more than 52,000 miles? What is the probability that a mean of 25 tires will last less than...

Suppose that the average length of telephone calls made by teenagers is a normally distributed variable...

Suppose that the average length of telephone calls made by teenagers is a normally distributed variable with mean and standard deviation given in columns 1 and 2 of Table B (LAB4B.DAT). mean: 42.6 standard deviation: 17.96 8. What is the probability that a random telephone call will last a length of time that is within one standard deviation of the mean (± 1 standard deviation)? 9. What is the proportion of telephone calls that last a length of time that...

Long distance telephone calls are normally distributed with a mean of 8 minutes and a standard...

Long distance telephone calls are normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes. If random samples of 25 calls were selected, what is the probability that telephone calls would be between 7.83 and 8.2 minutes? If random samples of 25 calls were selected, what is the probability that telephone calls would be at most 8.2 minutes? c. If random samples 100 calls were selected, what is the probability that telephone calls would be between...

The life of a ventilator is normally distributed with a mean of 9000 hours and a...

The life of a ventilator is normally distributed with a mean of 9000 hours and a standard deviation of 500 hours. (a) What is the probability that the ventilator fails before 8000 hours? (b) What is the life in hours that is exceeded by 96% of the ventilators? (c ) If 20 such ventilators are used in a hospital, and they are assumed to fail independently, what is the probability that all 20 are still operating after 7500 hours?

The life in hours of a certain type of lightbulb is normally distributed with a known...

The life in hours of a certain type of lightbulb is normally distributed with a known standard deviation of 10 hours. A random sample of 15 lightbulbs has a sample mean life of 1000 hours. What would the 99% lower-confidence bound L on the mean life be, rounded to the nearest integer?

The life expectancy of a brand of light bulbs is normally distributed with a mean of...

The life expectancy of a brand of light bulbs is normally distributed with a mean of 1500 hours and a standard deviation of 75 hours. A. What is the probability that a bulb will last between 1500 and 1650 hours. The life expectancy of a brand of light bulbs is normally distributed with a mean of 1500 hours and a standard deviation of 75 hours. A. What is the probability that a bulb will last between 1500 and 1650 hours....

iPhone 6 battery life ~ The life of a fully charged iPhone 6 is normally distributed...

iPhone 6 battery life ~ The life of a fully charged iPhone 6 is normally distributed with an average of 13 hours and a standard deviation of 1.5 hours. What is the life of a fully charged iPhone 6 battery for the 20th percentile? Enter your answer to 4 decimal places. Your Answer: Question 1 options: Answer

Subjects