Answer: Correct critical value = 2.2622
Step-by-step explanation:
Confidence interval for population mean when population standard deviation is unknown:
, where
= sample mean, n= sample size, s= sample standard deviation,
= two-tailed t value.
As per given: n= 10
degree of freedom : df = n-1=9
Critical t-value :
So, the 95 percent confidence interval estimate for the mean :
The 95 percent confidence interval estimate for the mean:(190.14, 295.06)