SOLUTION: Hi, Can you please help me with this question? A study of 100 QDA professors showed that the time to create a test question was 13.0 minutes. The standard deviation of the popula

Question 45469: Hi,
Can you please help me with this question?
A study of 100 QDA professors showed that the time to create a test question was 13.0 minutes. The standard deviation of the population was 2. Find the 90% confidence interval of the population mean.
Thanks for your help
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A study of 100 QDA professors showed that the time to create a test question was 13.0 minutes. The standard deviation of the population was 2. Find the 90% confidence interval of the population mean.
Margin of error = 1.645(2/sqrt100)=0.329
Confidence interval = (13-0.329,13+0.329)
=(12.671,13.329)
Cheers,
Stan H.

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