Question

Gerda discovers that the lifetime of light bulbs is normally distributed with mean 1000 hours and standard deviation 100 hours. if gerda buys 50 bulbs, how many of them are expected to last less than 800 hours? give your answer correct to the nearest integer.

Answer 1

At least 50 of them are bound to last that much and she is on the right track and keep going you should get it soon