Question

According to a Pew Research Center study, in May 2011, 41% 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 378 community college students at random and finds that 162 of them have a smart phone. Then in testing the hypotheses:

H0: p = 0.41 versus

Ha: p > 0.41,

what is the test statistic?

Answer 1

Solution :

Given that,

= 0.41

1 - = 0.59

n = 378

x = 162

Point estimate = sample proportion = = x / n = 0.429

Test statistic

z = ( - ) / *(1-) / n

= ( 0.429 - 0.41) / (0.41*0.59) / 378

= 0.73

The Test statistic is z = 0.73