Question

A simple random sample of size n is drawn. The sample​ mean is found to be 17.6​, and the sample standard​ deviation, s, is found to be 4.7.

A). Construct a 95​% confidence interval about if the sample​ size, n, is 51.

Answer 1

We have given that,              
              
Sample mean =17.6      
Sample standard deviation =4.7  
Sample size =51      
Level of significance=1-0.95=0.05      
Degree of freedom =50      
              
t critical value is (by using t table)=   2.01      
              
Confidence interval formula is   


=(16.28,18.92)          
              
              
              
Lower confidence limit=   16.28      
              
Upper confidence limit=   18.92