Exam 1 Solutions - Regression Analysis | BA 303, Exams of Introduction to Business Management

Download Exam 1 Solutions - Regression Analysis | BA 303 and more Exams Introduction to Business Management in PDF only on Docsity! Name Student [D: BA 303 - Fall 2006 - Exam 1 You have 70 minutes to complete this exam. You may use calculators subject to the caveats identified on the course syllabus. You may not consult any other resources which have not been provided by the instructor. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. Each question is worth 2 points, 1, In hypothesis testing, the tentative assumption about the population parameter is a. the alternative hypothesis CD the null hypothesis c. either the null or the alternative d. None of these alternatives is correct. to The p-value is a probability that measures the support (or lack of support) for the @& null hypothesis b. alternative hypothesis c. either the null or the alternative hypothesis d. sample statistic 3. The p-value a. is the same as the Z statistic b, measures the number of standard deviations from the mean c. is adistance (& isa probability 4. In hypothesis testing if the null hypothesis is rejected, a. no conclusions can be drawn from the test the alternative hypothesis is true c. the data must have been accumulated incorrectly d. the sample size has been too small 5. The level of significance is the a. maximum allowable probability of Type II error (© maximum allowable probability of Type I error ¢. same as the confidence coefficient d. same as the p-value 6. The error of rejecting a true null hypothesis is e a Type I error . a Type IJ error c. is the same as B d. committed when not enough information is available Name: 7. The probability of making a Type | error is denoted by @« b. B ec 1-a do 1-8 8. A soft drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of soft drink. Any over filling or under filling results in the shutdown and readjustment of the machine. To determine whether or not the machine is properly adjusted, the correct set of hypotheses is a. Ho: p< 12 Hy: p< 12 b. Ho: ps 12 Hy: we > 12 c. Ho pel2 Hy p=l2 Ho: w= 12 Hy: p 4 12 9. Ifa hypothesis is rejected at the 5% level of significance, it a. will always be rejected at the 1% level b. will always be accepted at the 1% level c. will never be tested at the 1% level © may be rejected or not rejected at the 1% level 10, For a two-lailed test at 86.12% confidence, Z = a. 1.96 1.48 ce. 1,09 d. 0.86 11. For a two-tailed test, a sample of 20 at 80% confidence, t = 1,328 2.539 ce. 1.325 d. 2.528 2 2. To construct an interval estimate for the difference between the means of two populations when the standard deviations of the two populations are unknown, we must use a t distribution with (let n, be the size of sample | and n> the size of sample 2) a. (n) + hy) degrees of freedom b. (m+ m2 - 1) degrees of freedom © (a1 + nm - 2) degrees of freedom d. m-ng+2 Name: Problems and Short Answer Complete the following questions in the space provided and shew the appropriate calculations (you may use the back side of the page if needed). 26. {15 points}A national automobile association has claimed that the average price for a gallon of gasonline was $2.75. Suppose you wish to test this claim and subsequently undertook a survey to collect data on the price of gasonline. The following are the summary statistics resulting from the survey: x=3.1 s=l.l n, =31 a) {4 points} State the correct hypothesis to be tested: Verglm ot a 7s £2, ° 34 Hy: A# 2.75 7 b) {5 points} Compute the appropriate test statistic: VLr6/on x - 2.7, ~ 2.78 4: Ay ERE, RIS L727 nh Rl a: As ~ Ly BL As rors 4: Aye ~32,0 26 Name: c) {3 points} Using a=0.10, use the tables to find the appropriate critical value(s) and state the correct conclusion whether or not to reject the null hypothesis. a~Aall pest ar O10 , haf = B-ts30 Af Agsa ow A = ee; 1007 a O.fe 0.08 a a Verolen 4 oe L772 Papel Ry 'eot He 2 ke ~L77 SRR Re et Y 3 Ae 2.005 f. Reject Mh % ko srtoas '. Reect Ke d) {3 points} Using a=0.05, use the tables to find the appropriate critical value(s) and state the correct conclusion whether or not to reject the null hypothesis. A, . _A# = 2,0%2 ss x Version L Do Mot Rej ret 4, a: Do Mok Re cok Ke 31 Be Mot Rect Ae G ‘ &, Myr ky tot H. Name: 27. {15 points} You are interested in determining whether the variance between two different types of cars are equivalent. In order to test this hypothesis for two different models of automobiles, samples are taken and the following information is collected. Model A Model B Sample Size 26 31 Sample Mean 28 25 Sample Variance 16 9 a) {5 points} State the correct hypothesis to be tested: ye: Ceo t a Ne OR #6 a b) {5 points} The test of hypothesis will be based on an F test. Compute the appropriate test statistic: 2a = * / ore fe 1. 779