H524e-PS8-Solutions - Readings from the textbook Chapters...

Info icon This preview shows pages 1–3. Sign up to view the full content.

Readings from the textbook Chapters 15 & 16 Problems to be turned in for grading Chapter 15: 8 (hint: part c is asking you to use the methods from week 7) (10 points) a. H 0 = P 1 = P 2 : The population proportion of students who drove while drinking is the same in the two calendar years (before and after the legal drinking age was raised). H a = P 1 ≠ P 2 : The population proportion of students who drove while drinking is different in the two calendar years (before and after the legal drinking age was raised). Pearson chi2(1) = 55.3553 Pr = 0.000 Total 2,637 2,657 5,294 2 1,387 1,666 3,053 1 1,250 991 2,241 row 1 2 Total col . tabi 1250 991 \ 1387 1666, chi2 The p-value is 0.000, so we reject the null. We can accept the alternative hypotheses that driving while drinking was different in the two calendar years. b. We recognize that in the two years (1983 and 1987), there was a change in the behavior of college-age drinking while driving. c. ^ p 1 = x 1 n 1 , ^ p 2 = x 2 n 2 ^ p 1 = 1250 2637 = 0.47 , ^ p 2 = 991 2657 = 0.37
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

( 1 n 1 ) +( 1 n 2 ) ¿ ^ p ( 1 ^ p ) ¿ ¿ z = ( ^ p 1 ^ p 2 ) ( p 1 p 2 ) ¿ ¿ ( .47 .37 ) .42 ( .58 ) 2637 +( .42 ( .58 ) 2657 ) .000184 ¿ 0.1 ¿ ¿ ¿ 7.37 7.37 > 1.96, so, like the Chi-square test, we reach the same conclusion and reject the null. d. ^ p 1 ( 1 ^ p 1 ) n 1 + ^ p 2 ( 1 ^ p 2 ) n 2 ( ^ p 1 ^ p 2 ) + z a 2 = ¿¿ .47 ( .53 ) 2637 + .37 ( .63 ) 2657 0.1 ± 1.96 = ¿¿ 0.1 ± 1.96 = .0001822 0.1 ± .026 CI = (0.074, 0.126) e. The CI does not contain 0, and I would not have expected it to since the null was rejected.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern