Question

The popping-times of the kernels in a certain brand of microwave popcorn are

Answer 1

Answer:

The z-score for this kernel is -2.3

Step-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

Answer 2

Answer:

-2.3

Step-by-step explanation: