A manufacturer of hard drives knows that the average life of a hard drive is five years with a standard deviation of one year. If he only wants to warranty the drive for three years, what proportion of hard drives should he expect to replace? Assume the normal distribution.
Solution. Let X be the life of a hard drive. By the given information, we know that X follows a normal distribution with mean 5 years and a standard deviation of one year. If he only wants ...
This solution consists of a detailed explanation of computing a probability of a normal distribution.