A market researcher wants to estimate the amount of money that a Christmass hopper will spend on Christmas presents. How largest sample size should she take to be 99% confidence that her error will be...

A market researcher wants to estimate the amount of money that a Christmass hopper will spend on Christmas presents. How largest sample size should she take to be 99% confidence that her error will be less than $2, knowing the standard deviation is $30.