Posted by Anonymous on Monday, September 13, 2010 at 9:53am.
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.
A.) 100%
B.) 5%
C.) 99.18%
D.) 0.82%
E.) Cannot be determined

statistics  PsyDAG, Monday, September 13, 2010 at 12:13pm
Z = (scoremean)/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.