Question

A cell phone company says that a fully charged battery lasts 14 hours. In reality, each battery behaves a little differently. For a large quantity of fully charged batteries, the mean length of time that batteries last is 14 hours, with a standard deviation of 1 hour. Assume that the lengths of time that battery charges last can be modeled by a normal distribution.

What percent of fully charged cell phone batteries would be expected to last longer than 14 hours?

Answer 1

The percentage is 50%

Explanation:

From the question we are told that

The mean is
`\mu = 14 \ hours`

The standard deviation is
`\sigma = 1 \ hour`

Generally on the normal distribution curve the mean divides the curve into two. with the half to the left of the mean (50% to the left )representing the percentage of the batteries that will last less than 14 hours and the area under the curve to the right (50% to the right)representing the percentage of batteries that will last longer than mean (14 hours )

Hence the percentage of the cell phone batteries that will be expected to last longer than 14 hours is 50%