Question

Suppose that you are testing the hypotheses Upper H 0​: p=0.21 vs. Upper H Subscript Upper A​: p not equals0.21. A sample of size 200 results in a sample proportion of 0.28.

a) The 90​% confidence interval for p is ​( , ​). ​(Round to three decimal places as​ needed.)

Answer 1

We have given here,              
              
      
n=200          
Estimate for sample proportion=0.28  
Level of significance is =1-0.90=0.1      
Z critical value(using Z table)=1.645      
              
Confidence interval formula is              


=(0.228,0.332)