Answer:
Step-by-step explanation:
The confidence interval for population mean is given by :-
, where n=sample size
= sample mean
=sample standard deviation
= critical t-value (for two tailed )
Let be the confidence interval for the population mean mercury concentration.
As per given , we have
Sample size : n= 28
degree of freedom = 27 [df=n-1]
Sample mean : cc/cubic meter
Sample standard deviation : s= 0.0036
Significance level :
Critical two-tailed test value :
(Using t-distribution table.)
We assume the population is approximately normal.
Now, the 98% confidence interval for the population mean mercury concentration will be :-
Required confidence interval :