Q:

The popping-times of the kernels in a certain brand of microwave popcorn arenormally distributed with a mean of 150 seconds and a standard deviation of10 secondsThe first kemel pops 127 seconds after the microwave oven is started, Whatis the z:score of this kernel? Round your answer to two decimal places.

Accepted Solution

A:
Answer:The z-score for this kernel is -2.3Step-by-step explanation:* Lets revise how to find the z-score - The rule the z-score is z = (x - μ)/σ , where # x is the score # μ is the mean # σ is the standard deviation * Lets solve the problem - The popping-times of the kernels in a certain brand of microwave   popcorn are  normally distributed- The mean is 150 seconds- The standard deviation is 10 seconds- The first kernel pops is 127 seconds- We want to find the z-score for this kernel∵ z-score = (x - μ)/σ∵ x = 127 ∵ μ = 150∵ σ = 10∴ z-score = (127 - 150)/10 = -23/10 = -2.3* The z-score for this kernel is -2.3