Answer: (20.86, 22.52)
Step-by-step explanation:
Formula to find the confidence interval for population mean :-
, where = sample mean.
z*= critical z-value
n= sample size.
= Population standard deviation.
By considering the given question , we have
n= 58
Using z-table, the critical z-value for 95% confidence = z* = 1.96
Then, 95% confidence interval for the amount of time spent on administrative issues will be :
Hence, the 95% confidence interval for the amount of time spent on administrative issues = (20.86, 22.52)