SOLUTION: 10.) The average cost of XYZ brand running shoes is $83 per pair, with a standard deviation of $8. If nine pairs of running shoes are selected, find the probability that the mean c

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Question 187884This question is from textbook Elementary statistics
: 10.) The average cost of XYZ brand running shoes is $83 per pair, with a standard deviation of $8. If nine pairs of running shoes are selected, find the probability that the mean cost of a pair of shoes will be less than $80. Assume the variable is normally distributed.
Thanks! This question is from textbook Elementary statistics

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The average cost of XYZ brand running shoes is $83 per pair, with a standard deviation of $8. If nine pairs of running shoes are selected, find the probability that the mean cost of a pair of shoes will be less than $80. Assume the variable is normally distributed.
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z(80) = (80-83)/8 = -0.3750
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P(x < 80) = P(z < -0.3750) = 0.3538...
Cheers,
Stan H.