Answer:
The percentage is 50%
Step-by-step explanation:
From the question we are told that
The mean is
The standard deviation is
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%