# Question: A company services copiers A review of its records shows

A company services copiers. A review of its records shows that the time taken for a service call can be represented by a normal random variable with a mean of 75 minutes and a standard deviation of 20 minutes.

a. What proportion of service calls takes less than 1 hour?

b. What proportion of service calls takes more than 90 minutes?

c. Sketch a graph to show why the answers to parts (a) and (b) are the same.

d. The probability is 0.1 that a service call takes more than how many minutes?

a. What proportion of service calls takes less than 1 hour?

b. What proportion of service calls takes more than 90 minutes?

c. Sketch a graph to show why the answers to parts (a) and (b) are the same.

d. The probability is 0.1 that a service call takes more than how many minutes?

## Answer to relevant Questions

Scores on an achievement test are known to be normally distributed with a mean of 420 and a standard deviation of 80. a. For a randomly chosen person taking this test, what is the probability of a score between 400 and ...Given a random sample size of n = 900 from a binomial probability distribution with P = 0.10 do the following: a. Find the probability that the number of successes is greater than 110. b. Find the probability that the number ...The tread life of Stone Soup tires can be modeled by a normal distribution with a mean of 35,000 miles and a standard deviation of 4,000 miles. A sample of 100 of these tires is taken. What is the probability that more than ...A professor sees students during regular office hours. Time spent with students follows an exponential distribution with a mean of 10 minutes. a. Find the probability that a given student spends fewer than 20 minutes with ...A random variable X is normally distributed with a mean of 100 and a variance of 500 and a random variable Y is normally distributed with a mean of 200 and a variance of 400. The random variables have a correlation ...Post your question