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
10 seconds
the first kemel pops 127 seconds after the microwave oven is started, what
is the z: score of this kernel? round your answer to two decimal places.

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

$25

step-by-step explanation:

25 - 4.50 = 20.5

20.5 / 2 = 10.25

10.25 + 10 = 20.25

20.25 - 12.50 = 7.75

therefore the answer is $25 as shown as the first number.

fd

step-by-step explanation: