Question

At a certain bank, we have the following independent random samples of balances on the checks account statements for customers of two of its branches:

Branch office	Number of checks accounts	Sample´s mean of balances	Sample´s standard deviaton
North	12	$1,100.00	$120.00
South	10	$950.00	$100.00

Determine the 90% confidence interval for the difference in balances at the two branches. Suppose the population standard deviations are equal.

With a 90% confidence level, you can ensure that the average balance in the North branch is greater than that of the South branch, being the difference between $ 67.70 and $ 232.30

Answer 1