Question

Brand A car batteries have a warranty of 60 months. The warranty given by the company depends upon the average life of the batteries. The life of the batteries is normally distributed with a mean of 62 months and a standard deviation of 2 months. What percent of the batteries will be working after 64 months?
A. 16%
B. 25%
C. 68%
D. 5%

Answer 1

well 64 is 1 standard deviation above the mean...

so it eliminates the 50% below the mean and the 34% that fall within 1 standard deviation above the mean

so the calculation should be

Percentage = 100 - 50 -34

hope it helps

Answer 2

100-50-34=16% (A)

Answer 3

that would be my answer as well...

if you need to check, google the normal distribution

and look at some images... they will show the percentages...

hope it helps

Answer 4

thank you