Quiz on Hypothesis Testing and Confidence Intervals, Quizzes of Probability and Statistics

Download Quiz on Hypothesis Testing and Confidence Intervals and more Quizzes Probability and Statistics in PDF only on Docsity! Quiz # 6 May 20, 2008 Name: Directions: Make sure to read each problem carefully. Make sure to show all of your work to receive full credit. Problem 1. A Martian scientist wants to challenge the notion that the average adult female Martian height is 62 quiggles. The scientist isn’t sure if the average height is taller or shorter than 62 quiggles, but she suspects that it is different from 62 quiggles. (a) State what her null and alternative hypotheses should be. H0 : µ = 60 Ha : µ 6= 60 The scientist chooses an SRS of 12 adult female Martians. The heights of the 12 Martians (in quiggles): 59 60 61 62 63 63 63 64 64 66 67 68 (b) Is it reasonably safe to use the t procedures on this sample? Why or why not? The data is reasonably symmetric with no outliers, so we may use the t-procedures if we like. (c) Assuming it is safe, carry out the test and report your conclusion. Solution. x̄ = 63.3333 s = 2.7080 t = 63.3333− 62 2.7080/ √ 12 = 1.7056 Using table C, we see that 0.10 < P < 0.20 (using df = 11). Given the P-value, we fail to reject the null hypothesis. There is not good evidence that the average adult male Martian has height different from 62 quiggles.