Question

When calculating confidence intervals within a project where I have found the average of a group of 50 who have traveled a distance of 55 miles to work, how do you calculate a confidence interval using standard deviation and a t distribution? What is the confidence interval in? I don't understand how it pertains to this subject matter.

Answer 1

So in your case sample size becomes, n = 50

Hence degree of freedom is, df = n - 1 = 49

Nect you have to decide what level of confidence interval you want to calculate (90%, 95%, 99%). As you increase the level band of interval increases.

The formula is

So, the confidence interval signifies how confident are you that population mean will lies in this interval based on sample mean.

Here, in your case, it will signify with how much confidence you can say in a population that average number of people who have walked more than 55 miles.

This band is used to estimate population mean based on the data of sample drawn out from population.