Magic Video Games, Inc., sells an expensive video computer games package. Because the package is so expensive, the company wants to advertise an impressive guarantee for the life expectancy of its computer control system. The guarantee policy will refund full purchase price if the computer fails during the guarantee period. The research department has done tests which show that the mean life for the computer is 25 months, with a standard deviation of 7 months. The computer life is normally distributed. How long can the guarantee period be if the management does not want to refund the purchase price on more than 22% of the Magic Video packages?

Question 16 options:

a)	a. between 29 and 30 months

b)	b. between 21 and 22 months

c)	c. between 13 and 14 months

d)	d. around 25 months plus or minus 22%

e)	e. between 11 and 12 months