4 The life expectancy of a memory chip is 4 years a Find the

4. The life expectancy of a memory chip is 4 years. (a) Find the probability that a chip will last more than 5 years. Hint. This is exponential with lambda = 1/4. (b) If a second chip is used to replace the first when it fails, what is the probability you will still have a good chip after 5 years? Hint. This is a gamma distribution. (c) If two chips start being used at the same time, what is the probability at least one of them is still good after 5 years?

Solution

a) 0.2865

USE EXPODIST function in excel.

b) 0.9907