Arandom sample of 89 tourists in chattanooga showed that they spent an average of $2860 (in a week) with a standard deviation of $126; and a sample of 64 tourists in orlando showed that they spent an average of $2935 (in a week) with a standard deviation of $138. we are interested in determining if there is any significant difference between the average expenditures of all the tourists who visited the two cities.

yup the answer is

credit history is used by lenders to determine whether you are a 'risky' person to give their money to.

having a short history provide very little data for the lenders. they wouldn't be able to determine your credit behavior from such a small samples. even if they are perfect.

having long credit history with few blemishes provide larger and more accurate data for the lenders to predict your credit behavior.