Statistical Analysis in ECSE4500: Hypothesis Testing and Significance Levels, Assignments of Statistics

Download Statistical Analysis in ECSE4500: Hypothesis Testing and Significance Levels and more Assignments Statistics in PDF only on Docsity! ECSE4500 P.S.#11 Due 12/1/2008 (SOLUTIONS) Note: You may use any statistical package such as Excel, Matlab, Minitab, etc. However, if asked to compute a variable, please at least show the expression used for computing it. 1) With H0: 750=μ , and Ha: 750<μ and a significance level of .05, we reject H0 if z < -1.645; z = -2.14 < -1.645, so we reject the null hypothesis and do not continue with the purchase. At a significance level of .01, we reject H0 if z < -2.33; z = -2.14 > -2.33, so we don’t reject the null hypothesis and thus continue with the purchase. The P- value for this data is 0.016, so that’s why we rejected for .05 and don’t reject for .01. 2) With H0: 5.=μ , and Ha: 5.≠μ we reject H0 if 1,2/ −> ntt α or 1,2/ −−< ntt α a. 1.6 < t.025,12 = 2.179, so don’t reject H0 b. -1.6 > -t.025,12 = -2.179, so don’t reject H0 c. – 2.6 > -t.005,24 = -2.797, so don’t reject H0 d. –3.9 < the negative of all t values in the df = 24 row, so we reject H0 in favor of Ha. 3) p = true proportion of all donors with type A blood H0: p = .40 Ha: p ≠ .40 ( ) ( ) n p npp pp z oo o /60.40. 40.ˆ /1 ˆ − = − − = Reject H0 if z ≥ 2.58 or z ≤ -2.58 ( ) 667.3 04. 147. 150/60.40. 40.150/82 == − =z Reject H0. The data does suggest that the percentage of all donors with type A blood differs from 40%. (at the .01 significance level). Since the z critical value for a significance level of .05 is less than that of .01, the conclusion would not change.