Question

A poll of 2,160 randomly selected adults showed that 92​% of them own cell phones. The technology display below results from a test of the claim that 91​% of adults own cell phones. Use the normal distribution as an approximation to the binomial​ distribution, and assume a 0.01 significance level to complete parts​ (a) through​ (e). Test of p=0.91 vs p≠0.91

Sample=1 x=1,981 n=2,160 sample p= .917130 95%CI= ​(0.901850,0.932409) z-value=1.16 p-value= .247

Answer 1

Null hypothesis         

   
              
Alternative hypothesis

           
              
We have for given example,              
Population proportion value is =0.91          
x=1981          
              
n=2160          
Level of significance =   0.01          
Estimate for sample proportion = 0.917130      
              
Z test statistic formula for proportion

      
P-value   =0.247 ...........................by using Excel command =2*(1-NORMSDIST(1.16)) or by using Z table.   
Decision:Do not reject   H0