According to a Pew Research Center study, in May 2011, 33% of all American adults had a smart phone (one which the user can use to read email and surf the Internet). A communications professor at a university believes this percentage is higher among community college students. She selects 387 community college students at random and finds that 142 of them have a smart phone. Then in testing the hypotheses: H0: p=0.31 versus
H: p > 0.31,
what is the test statistic?