Question

The popping-times of the kernels in a certain brand of microwave popcorn are normally distributed with a mean of 150 seconds and a standard deviation of 11 seconds.

The first kernel pops 126 seconds after the microwave oven is started. What is the z-score of this kernel?

Also what in the world is a z-score?

Answer 1

the right answer is -2.18

Explanation:

Answer 2

The z-score of the data can be calculated by the formula expressed as follows:

z = ( score - mean ) / standard deviation
z = (126 - 150 ) / 11 = -2.18

A z-Score is a statistical measurement of a score's relationship to the mean in a group of scores. A Z-score of 0 means the score is the same as the mean.