posted by Anonymous .
Solve the problem. The lifetime of a new brand of light bulb can be described by a Normal model with a mean of 2000 hours and a standard deviation of 250 hours. Find the percentage of light bulbs that will last more than 2600 hours.
E.) Cannot be determined
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.