The average life expectancy of computers produced by Ahmadi, Inc. is 7 years with a standard deviation of 10 months. Assume that the lives of computers are normally distributed. Suggestion: For this problem, convert ALL of the units to months. (You may need to use the appropriate appendix table or technology to answer this question.)

(a)What is the probability that a randomly selected computer will have a life expectancy of at least 8 years? (Round your answer to four decimal places.)

(b)Computers that fail in less than 6.5 years will be replaced free of charge. What percentage of computers are expected to be replaced free of charge? (Round your answer to two decimal places.) %

(c)What are the minimum and the maximum life expectancy of the middle 95% of the computers' lives? Give your answers in months. (Round your answers to one decimal place.)minimum monthsmaximum months

Minimum:

Maximum

(d)The company is expecting that only 153 of this year's production will fail in less than 4 years and 8 months. How many computers were produced this year? (Round your answer to the nearest integer.)