Question

Assume that the samples are independent and that they have been randomly selected. Construct a​ 90% confidence interval for the difference between population proportions p1-p2. Round to three decimal places. x1=12​, n1=45 and x2=21​, n2=51

A.

-0.301 <p1-p2< 0.011

B.

0.453 <p1−p2 < 0.079

C.

0.109 <p1−p2< 0.425

D.

0.081 <p1−p2< 0.453

Answer 1

We have given,              
              
x1=12          
n1=45          
              
x2=21          
n2=51          
              
Level of significance =1-0.90=   0.1          
Z critical value (by using Z table)=1.645
Estimate for sample proportion 1
              
Estimate for sample proportion 2
  
Confidence interval formula is              


=(-0.301,0.011)     

A. -0.301 <p1-p2< 0.011