A 30-minute consumer survey mailed to 500 adults aged 25–34 included a $10 ...

     A   30-minute consumer survey mailed to 500 adults aged 25–34 included a $10 gift   certificate to   Borders. The same survey was   mailed to 500 adults aged 25–34 without the gift certificate. There were 185   responses from the first group and 45 from the second group. (a) At α = .025, did the gift certificate increase the response rate by at   least 20 percent?