# Question: The time that it takes an emergency car repair service

The time that it takes an emergency car repair service to arrive at a car that has broken down is a normally distributed random variable, with a mean of 42 minutes and a standard deviation of 12 minutes. What is the probability that a customer will have to wait more than 45 minutes for help to arrive?

## Answer to relevant Questions

In Chapter 6, you will see that the normal distribution can sometimes be used to approximate the binomial distribution. This exercise is designed to illustrate how good the normal approximation to the binomial can be. a. ...The marks in an economics class are normally distributed, with a mean of 65% and a standard deviation of 12%. a. What percentage of the class passed (that is, received a mark of 50% or higher)? b. What percentage of the ...A tire company claims that no more than 1% of its tires are defective. A national survey shows that 8 out of 500 tires purchased in the last year from this company were defective. Does the sample provide evidence that the ...Suppose a college claims that its graduates from the business program earn at least $40,000 a year, on average, in the first year after graduation. Assume that the year-after-graduation salaries are normally distributed, ...Use the distributions from Exercise 1 to answer the following questions. a. What is the probability that an individual student will be taller than 180 centimetres? b. Suppose a random sample of 25 students is selected from ...Post your question