This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: EON317 Midterm Examination #2 Form A Professor Manochehr Rashidian March 13, 2008 1. (40 POINTS) a. (15 points) Let μ denote the average speed over the strech. Then the null and the alternative hypotheses are H : μ = 70 , H a : μ > 70 . Based on the data set, n = 8, ¯ x = 75 . 3750, s = 6 . 4351 and the test statistic t = 75 . 3750 70 6 . 4351 / √ 8 = 2 . 3625 . Since t . 100 = 1 . 415 < t = 2 . 3625, we REJECT the null hypothesis, H . Therefore, we conclude that the average speed of traveling over a particular strectch of a highway exceeds the legal limit of 70 MPH at 10% significance level. b. (10 points) Drawing upon the tdistribution table, we can infer that . 025 < p value < . 050 since 1 . 895 = t . 050 < t < t . 025 = 2 . 365. So the null hypothesis will be rejected at significance level α = . 05 but cannot be rejected at α = . 025. c. (5 points) We need to assume that each sample is from a underlying common (approximately) normal distribution. d. (10 points) A 90% confidence interval is ¯ x ± t α/ 2 s √ n = 75 . 3750 ± 1 . 895 6 . 4351 √ 8 1 = 75 . 3750 ± 1 . 895 × 2 . 2752 = 75 . 3750 ± 4 . 3115 , which is [71 . 06 , 79 . 69]. We are 90% confident that the average speed of traveling over a particular stretch of highway lies between 76.1 MPH and 79.7 MPH. So we have 90% confidence that the average speed exceeds 70 MPH.speed exceeds 70 MPH....
View
Full
Document
This note was uploaded on 09/11/2008 for the course ECON 317 taught by Professor Safarzadeh during the Spring '07 term at USC.
 Spring '07
 Safarzadeh

Click to edit the document details