Two random samples are taken, with each group asked if they support a particular candidate. a summary of the sample sizes and proportions of each group answering ``yes'' are given below: pop1: n1=92 p1=0.768 pop2: n2=95 p2=0.646 suppose that the data yields (-0.0313, 0.2753) for a confidence interval for the difference p1-p2 of the population proportions. what is the confidence level? (give your answer in terms of percentages.)

And we got so then the value for and then the confidence level is given by: represent the real population proportion for 1

represent the estimated proportion for 1

is the sample size required for 1

represent the real population proportion for 2

represent the estimated proportion for 2

is the sample size required for 2

represent the critical value for the margin of error  

The population proportion have the following distribution  

The confidence interval for the difference of two proportions would be given by this formula  

For this case we have the confidence interval given by: (-0.0313,0.2753). From this we can find the margin of erro on this way:

And we know that the margin of erro is given by:

We have all the values except the value for

So we can find it like this:

And solving for we got:

And we can find the value for with the following excel code:

"=1-NORM.DIST(2.326,0,1,TRUE)"

And we got so then the value for and then the confidence level is given by: or 98%