SOLUTION: 12869The 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 13 seconds.
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-> SOLUTION: 12869The 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 13 seconds.
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Question 918253: 12869The 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 13 seconds.
The first kernel pops 128 seconds after the microwave oven is started. What is the z-score of this kernel? Round your answer to two decimal places. Answer by AlgebraLady88(44) (Show Source):
You can put this solution on YOUR website! The z score is the number of standard deviations from the mean. The formula for this is
z= (sample value - sample mean )/ standard deviation
z= (x-m)/s
z= (128-150)/13
z= -1.6923077
z= -1.69 ( to two decimal places)
This shows that the sample 128 secs falls -1.69 standard deviations below the mean.
