In a random sample of 27 people, the mean commute time to work was 30.4 minutes and the standard deviation was minutes. Assume the population is normally distributed and use a t-distribution to construct a % confidence interval for the population mean mu. What is the margin of error of mu?

The 95% CI is

The margin of error is 2.9 minutes.

Step-by-step explanation:

The question is incomplete:

The sample standard deviation was 7.3 minutes.

Assume the population is normally distributed and use a t-distribution to construct a 95% confidence interval for the population mean mu.

The sample mean is 30.4

The sample standard deviation is 7.3

The sample size is 27.

The degrees of freedom are:

For a 95% CI and df=26, the critical value for t is t=2.056.

The margin of error can be calculated as:

The lower and upper bounds of the 95% CI are:

The 95% CI is then

the answer is 31.27mph

addition

step-by-step explanation: