4.A company estimates that 0.4% of their products will fail after the original warranty period but within 2 years of the purchase, with a replacement cost of $50.

If they offer a 2 year extended warranty for $5, what is the company's expected value of each warranty sold?

5. The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.7 days and standard deviation of 1.2 days. Use your graphing calculator to answer the following questions. Write the answers inpercentform. Round your answers to the nearest tenth of a percent.

a) What is the probability of spending less than 9 days in recovery? %

b) What is the probability of spending more than 4 days in recovery? %

c) What is the probability of spending between 4 days and 9 days in recovery? %