Practise selecting a two-sample z-interval when two independent samples are used to estimate a difference between contextual population proportions.
The campaign manager for a candidate for governor wants to estimate the difference between the percentage of voters who viewed an advertisement and favor the candidate and the percentage of voters who had not viewed the advertisement and favor the candidate. Two independent random samples of 500 voters were selected. One random sample consisted of voters who viewed the advertisement and the other random sample consisted of voters who had not viewed the advertisement. The table shows the frequencies of responses for those surveyed.
Which of the following is the most appropriate method for the campaign manager to use to estimate the difference between the percentages of voters who favor the candidate?
A one-sample z-interval for estimating a population proportion
A t-interval for estimating the slope of the least-squares regression line
A matched-pairs t-interval for estimating a mean difference
A two-sample z-interval for estimating a difference between sample proportions
A two-sample z-interval for estimating a difference between population proportions