Question

1. A Wall Street Journal poll (What's News Online, The Wall Street Journal, March 30, 2004, p. D7) asked respondents if they trusted energy-efficiency ratings on cars and appliances; 552 responded yes, and 531 responded no. a. At the 0.05 level of significance, use the six-step critical value approach to hypothesis-testing to try to prove that the percentage of people who trust energy-efficiency ratings differs from 50%. b. Use the five-step p-value approach. Interpret the meaning of the p-value.

Answer 1

ns: total no- of respondents (A) 2 SS2+531 = 1083 . Respondents who fouest (re)- 552... A p is proportion of respondents say yes? (a) The null and alternate hypothesis al. Ho! p=0.5 B Hai p 70.5 (two tailed) bo we will reject Ho.if edest statistic z>1.96 .2= P - R a 0.51-0.50 0.658- 861-1] To.sxos 0 0 0 [o 83 since z 2196, so we accept to and conclude that percentage of people who trust energy efficiency rating is not deffere from 0.5 or soy .. b) p value from a table is o.5105 since pralue 2005 so we fail to reject Ho and conclude that percentage of people who drust energy efficiency rating is not differ from 0.5 or soy