A dentist wants to estimate the average number of patients coming into her clinic each day. She estimates the standard deviation is 6 patients per day. If she wants to use a random sample of previous...

A dentist wants to estimate the average number of patients coming into her clinic each day. She estimates the standard deviation is 6 patients per day. If she wants to use a random sample of previous days for her sample, how many days should she include to be 95% sure her estimate is off by no more than 0.3 patients per day?