Question

A random sample of n=12 values taken from a normally distributed population resulted in the sample values below. Use the
sample information to construct 95 % confidence interval estimate for the population mean.

107 93 90 114 90 98 115 112 110 108 97 96
The 95% confidence interval is from $__________ to $__________ .
(Round to two decimal places as needed. Use ascending order.)

Answer 1

We have for given data,              
              
Sample mean =102.5      
Sample standard deviation =9.444  
Sample size =12      
Level of significance=1-0.95=0.05      
Degree of freedom =11      
              
t critical value is (by using t table)=2.201      

The 95% confidence interval is from $96.50 to $ 108.50