Question

The shelf life of a battery produced by one major company is known to be Normally distributed, with a mean life of 8 years and a standard deviation of 0.9 years. What value of shelf life do 16% of the battery shelf lives fall above? Round your answer to one decimal place.

Answer: years

Answer 1

Mean shelf life of battery = 8 Years and Standard Deviation = 0.9 years.

To find the value of battery shelf life which falls above 16% of battery shelf lives, we will have to calculate the Z-value at the point where probability is 0.16. This Z-value can be found using excel formula NORM.S.INV(0.16), this function takes the probability value as an argument. Z-value at 16% probability = -0.99

So, the value of battery shelf life which falls above 16% of battery shelf lives = Mean + Z-score*Standard Deviation = 8 - 0.99*0.9 = 7.1 Years(Rounded to one decimal)

Please upvote if the answer was useful :)