Question

Reserve Problems Chapter 4 Section 5 Problem 2 A laptop company claims up to 10.1 hours of wireless web usage for its newest laptop battery life. However, reviews on this laptop shows many complaints about low battery life. A survey on battery life reported by customers shows that it follows a normal distribution with mean 9.5 hours and standard deviation 30 minutes. (a) What is the probability that the battery life is at least 10.1 hours? Round your answer to four decimal places (e.g. 98.7654).

Answer 1

0.1151

Explanation:

Given that a laptop company claims up to 10.1 hours of wireless web usage for its newest laptop battery life. However, reviews on this laptop shows many complaints about low battery life. A survey on battery life reported by customers shows that it follows a normal distribution with mean 9.5 hours and standard deviation 30 minutes.

If X is the battery life then X is N(9.5, 0.5)

(we convert into one unit for calculations purpose here hours)

a) the probability that the battery life is at least 10.1 hours

=
`P(X\geq 10.1)\\=P(Z\geq (10.1-9.5)/(0.5) )\\= P(Z\geq 1.2)\\=0.1151`

we get the probability that the battery life is at least 10.1 hours is 0.1151