Answer: (60.858, 69.142)
Step-by-step explanation:
The formula to find the confidence interval for mean :
, where
is the sample mean ,
is the population standard deviation , n is the sample size and
is the two-tailed test value for z.
Let x represents the time taken to mail products for all orders received at the office of this company.
As per given , we have
Confidence level : 95%
n= 62
sample mean : hours
Population standard deviation : hours
z-value for 93% confidence interval: [using z-value table]
Now, 93% confidence the mean time taken to mail products for all orders received at the office of this company :-
Thus , 93% confidence the mean time taken to mail products for all orders received at the office of this company : (60.858, 69.142)
