A savings and loan association needs information concerning the checking account balances of its local customers. A random sample of 14 accounts was checked and yielded a mean balance of$664.14 and a standard deviation of$297.29. Assume that the population is normally distributed. Find a90% confidence interval for the true mean checking account balance for local customers. Round to two decimal places.

A.

$523.43 to$804.85

B.

$493.71 to$834.57

C.

$492.52 to$835.76

D.

$455.65 to$872.63

I'm most confused with understanding where to plug in each number into the equation when using my TI-84 Calculator