Determining the confidence interval for the mean

4. The owner of a business wanted to test how long employees were spending on the internet. A random sample of 49 employees showed a mean of 42 minutes and a standard deviation of 5.2 minutes. Find a 90% confidence for the mean.

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... minutes
Standard deviation= 5.2 minutes
Sample size= 49
Confidence interval= 90%
Therefore, Significance level= 0.10 = 1-0.9
Population standard deviation (Known, Not Known)= Not Known

No of tails= 2 (This is 2 tailed because we are calculating the ...