Question

A random sample of 20 students at a university showed an average age of 21.5 years and a sample standard deviation of 2.8 years. The 98% confidence interval for the true average age of all students in the university is?

Enter in the upper limit of your confidence interval. ( round to 4 decimal places)

Answer 1

We have given that,              
              
Sample mean =21.5      
Sample standard deviation =2.8  
Sample size =20      
Level of significance=1-0.98=0.02      
Degree of freedom =19      
              
t critical value is (by using t table)=   2.539      
              

Therefore, the upper limit of your confidence interval =23.0897