confodence interval= [ 81 - z(alpha)/2]*(27/81) ,81 - z(alpha)/2]*(27/81)]
so by putting values
--> 167 +/-
--> (161.12, 172.88)
b) it is seen from the data
have 95% confident that the population mean will be within this interval because this means that if you take 100 samples of size 81 in 95%
case the sample mean will fall in this interval
c) let n=required sample size,alpha=0.05
[z(alpha)/2]*(27/n) = 2
(by the question)
z(alpha)/2 can be found
from normal table .
Content will be erased after question is completed.
Enter the email address associated with your account, and we will email you a link to reset your password.
Forgot your password?