Assume that all variable are approximately normally distributed.

Chicago Commuters A sample of 14 commuters in Chicago showed the average of the commuting times was 33.2 minutes. If the standard deviation was 8.3 minutes, find the 95% confidence interval of the true mean.

Source: U. S. Census Bureau.

Step 1 of 2:

It is given that 33.2 minutes is the mean commuting time of a sample of 14 commuters and 8.3 minutes is the standard deviation.

Using this we need to find the 95% confidence interval for mean.