In the 1992 presidential campaign, H. Ross Perot received about 20% of the popular vote. As the 1996 campaign approached, a statistician wanted to test whether Perot had maintained the same level of support. He polled 100 people and found that 15 of them supported Perot. He will use a .01 level of significance. What is the value of the test statistic? a. –1.40 b. –1.25 c. 1.25 d. 1.40

Answer:The correct option is b.Step-by-step explanation:Given information:Population proportion = 20% = 0.2Sample proportion = [tex]\frac{15}{100}=0.15[/tex]Sample size = 100Let as assume that the sample is normally distributed.The formula for test statistics is[tex]z=\frac{p-P}{\sqrt{\frac{PQ}{n}}}[/tex]where,p is sample proportion.P is population proportion.Q is 1-Pn is sample size.The value of the test statistic is[tex]z=\frac{0.15-0.2}{\sqrt{\frac{0.2(1-0.2)}{100}}}[/tex][tex]z=\frac{-0.05}{0.04}[/tex][tex]z=-1.25[/tex]The value of test statistic is -1.25. Therefore the correct option is b.