Confidence Interval Estimation

I am totally clueless about stats. Please help me set up this problem
A well known children's shoe store wants to estimate the mean retail value of rain boots that it has in its inventory. A random sample of 20 rain boots indicates an average value of $25.59 and a standard deviation of $ 4.25.
a. Assuming a normal distribution, set up a 95% confidence interval estimate of the mean value of all rain boots in the store's inventory.
b. How can the results you obtained above help the store owner estimate the total value of his inventory?


TS Contributor
Our Examples section has a thread on Computing Confidence Intervals.

Using the lower and upper bound for the confidence interval, multiply each by the total inventory of shoes to estimate the total value of the inventory.