The lifetimes of light bulbs of a particular type are normally distributed with a meanof 370 hours and a standard deviationof 5 hours. What percentage of bulbs has lifetimes that lie within 1 standard deviation of the mean on either side?
Here is my answer:
According to the question, z=+/-1 for those that lie within 1 standard …
For this solution, first we calculate the z scores. Then in the following step, we used z score based p value to calculate the probability.