Answer:
The percentage is 50%
Step-by-step explanation:
From the question we are told that
The mean is [tex]\mu = 14 \ hours[/tex]
The standard deviation is [tex]\sigma = 1 \ hour[/tex]
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%