Claim: Fewer than 93​% of adults have a cell phone. In a reputable poll of 1021 ​adults, 88​% said that they have a cell phone. Find the value of the test statistic. The value of the test statistic is nothing. ​(Round to two decimal places as​ needed.)

Accepted Solution

Answer: -6.26Step-by-step explanation:Test statistic for population proportion is given by :-[tex]z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}[/tex], where p = population proportion.[tex]\hat{p}[/tex] = sample proportion.n= sample size.As per given , we have[tex]H_a:p<0.93[/tex]n= 1021[tex]\hat{p}=0.88[/tex] Then, the test statistic will be :-[tex]z=\dfrac{0.88-0.93}{\sqrt{\dfrac{0.93(1-0.93)}{1021}}}\\\\=\dfrac{-0.05}{\sqrt{0.0000637610186092}}\\\\=\dfrac{-0.05}{0.0079850496936}\\\\=-6.26170179506\approx-6.26[/tex]Hence, the value of the test statistic is -6.26 .