Television networks frequently run public opinion polls on issues of concern.Recently one network conducted a scientific poll asking a question concerning the approval rating of the way President Obama was handling the Iraq War.At about the same time a second network ran an online poll using a very similar question.The results of the two polls are summarized in the following table. We would like to test to see if the two polls are consistent with respect to the proportion who approve of President Obama's handling of the war (i.e. ,H₀: ). A statistic was calculated under the null hypothesis,which has the value 22.28.If the respondents in both polls can be considered to come from random samples,what is this statistic? A)It is approximately a t with 1 degree of freedom. B)It is a statistic with approximately a chi-square distribution with 3 degrees of freedom. C)It is a statistic with an approximate chi-square distribution with 1 degree of freedom. D)It is a z statistic. E)It is none of the above.

Question

Quizplus · Accepted Answer

The statistic being calculated under the null hypothesis is a chi-square statistic since it involves comparing counts in different categories (approvals and disapprovals) from two different samples. Since there are only two categories, we have only 1 degree of freedom for the chi-square distribution. Therefore, the correct choice is C.

Television Networks Frequently Run Public Opinion Polls on Issues of Concern.Recently