In developing patient appointment schedules a medical center

In developing patient appointment schedules, a medical center wants to estimate the mean time that a staff member spends with each patient. How large a sample should be taken if the desired margin of error is two minutes at a 95% level of confidence? How large a sample should be taken for a 99% level of confidence? Use a planning value for the population standard deviation of 6 minutes.

95% Confidence (to the nearest whole number):  

99% Confidence (to the nearest whole number):

Solution

a)
Compute Sample Size
n = (Z a/2 * S.D / ME ) ^2
Z/2 at 0.05% LOS is = 1.96 ( From Standard Normal Table )
Standard Deviation ( S.D) = 6
ME =2
n = ( 1.96*6/2) ^2
= (11.76/2 ) ^2
= 34.57 ~ 35      

b)

n = ( 2.58*6/2) ^2
= (15.48/2 ) ^2
= 59.91 ~ 60