In order to estimate the average daily down time,a manufacturer randomly sampled 41 days of production records and found a mean of 51.75 minutes and standard deviation of 7.9 minutes.A 90% confidence interval for the population mean is:
A)51.75 ± 4.76
B)51.75 ± 3.28
C)51.75 ± 2.08
D)51.75 ± 1.30

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The Answer of In order to estimate the average daily down time,a manufacturer randomly sampled 41 days of production records and found a mean of 51.75 minutes and standard deviation of 7.9 minutes.A 90% confidence interval for the population mean is:
A)51.75 ± 4.76
B)51.75 ± 3.28
C)51.75 ± 2.08
D)51.75 ± 1.30

In Order to Estimate the Average Daily Down Time,a Manufacturer