SOLUTION: 2. Spiffy Sports has determined that the mean time it takes to process an order placed on its website is 23 minutes with a standard deviation of 8 minutes. Suppose a random sample

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Question 1080764: 2. Spiffy Sports has determined that the mean time it takes to process an order placed on its website is 23 minutes with a standard deviation of 8 minutes. Suppose a random sample of 36 online orders are selected. 2 MARKS

a. What is the probability that the mean of the selected sample is less than 20 minutes?

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
. Spiffy Sports has determined that the mean time it takes to process an order placed on its website is 23 minutes with a standard deviation of 8 minutes. Suppose a random sample of 36 online orders are selected. 2 MARKS
a. What is the probability that the mean of the selected sample is less than 20 minutes?
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z(20) = (20-23)/(8/sqrt(8)) = -1.06
P(x-bar < 20) = P(z < -1.06) = normalcdf(-100,-1.06) = 0.1446
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Cheers,
Stan H.
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