Question

1. The amount of time an alkaline battery lasts is normally distributed with a mean life of
19 hours and standard deviation of 1.2 hours.
(a) 68% of all batteries will last between ____________ hrs. and _____________ hrs.
(b) 95% of all batteries will last between ____________ hrs. and _____________ hrs.
(c) What percent of the batteries will have a life that exceeds 16.6 hours? _________
(d) What percent of the batteries will have a life that lasts between 15.4 and 22.6 hours? ______
(e) If a company purchases 10,000 batteries, how many batteries are expected to last
 more than 17.8 hours? ___________
 between 15.4 and 20.2 hours? ____________

Answer 1

Dear your satisfaction is more important, I provided answers with detailed explanation. If you are satisfied with my explanations please THUMBS UP.. Thanks inadvance for your support dear....

Answers

(a) 68% of all batteries will last between 17.80665 hrs. and 20.19335 hrs.

(b) 95% of all batteries will last between 16.64804 hrs. and 21.35196 hrs.

(c) What percent of the batteries will have a life that exceeds 16.6 hours?

Answer : 97.72 %

(d) What percent of the batteries will have a life that lasts between 15.4 and 22.6 hours?

Answer: 99.73%

(e) If a company purchases 10,000 batteries, how many batteries are expected to last

more than 17.8 hours?

Answer: 8413 (reason is explained below)

between 15.4 and 20.2 hours?

Answer:  8400 (reason is explained below)