DOC PREVIEW
TAMU STAT 303 - ex3af03

This preview shows page 1-2 out of 5 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

STAT303: Secs 508-510Fall 2003Exam #3Form AInstructor: Julie Hagen Carroll1. Don’t even open this until you are told to do so.2. Be sure to mark your section number (508, 509 or 510) and your test form (A, B or C) on the scantron!3. There are 20 multiple-choice questions on this exam, each worth 5 points. There is partial credit. Pleasemark your answers clearly on the scantron. Multiple marks will be counted wrong.4. You will have 60 minutes to finish this exam.5. If you are caught cheating or helping someone to cheat on this exam, you both will receive a grade ofzero on the exam. You must work alone.6. This exam is worth 100 points, and will constitute 20% of your final grade.7. Good luck!1STAT302: 508-510 Exam #3, Form A Fall 20031. H0: µ = 4 vs. HA: µ > 3 is NOT a valid set ofhypotheses becauseA. we rarely know µ is practice.B. the population standard deviation is notgiven/known.C. 4 is not a plausible value for µ.D. there is not a practical significant differencebetween 3 and 4.E. both hypotheses could be true simultane-ously.GENDER TotalHOMETOWN | female | male |----------------------|--------|-------|-------lrgcity Count | 7 | 3 | 10Expected | 5.2 | 4.8 | 10.0----------------------|--------|-------|-------metro Count | 21 | 19 | 40Expected | 20.8 | 19.2 | 40.0----------------------|--------|-------|-------outside Count | 5 | 3 | 8Expected | 4.2 | 3.8 | 8.0----------------------|--------|-------|-------smlcity Count | 7 | 8 | 15Expected | 7.8 | 7.2 | 15.0----------------------|--------|-------|-------town Count | 12 | 15 | 27Expected | | | 27.0----------------------|--------|-------|-------Total Count | 52 | 48 | 100Expected | 52.0 | 48.0 | 100.0Chi-Square TestsValue df Sig. (2-sided)Pearson Chi-Sq 2.444 4 0.655a 3 cells (30.0%) have expected count less than 5.The minimum expected count is 3.84.2. What is the expected count for a female from atown?A. 12B. 13C. 14D. 15E. 273. What is the correct conclusion based on the out-put in the previous problem?A. Since there are cell counts less than 5, wecan’t use the χ2test; therefore, we can’tconclude anything.B. Although there are cell counts less than 5,we can still use the χ2test since each cellhas a count greater than 1 and there aremore than 4 cells. Our conclusion is thatgender and hometown are related.C. Although there are cell counts less than 5,we can still use the χ2test since each cellhas a count greater than 1 and there aremore than 4 cells. Our conclusion is thatgender and hometown are independent.D. Although there are cell counts less than 5,we can still use the χ2test since each cellhas a count greater than 1 and there aremore than 4 cells. Our conclusion is thatwe couldn’t prove gender and hometown arerelated.E. Although there are cell counts less than 5,we can still use the χ2test since each cellhas a count greater than 1 and there aremore than 4 cells. Our conclusion is thatwe couldn’t prove gender and hometown areindependent.4. What elements of a one-sample statistical testmay be affected by changing the sign of the al-ternative hypothesis test? (Assume the data,sample size, and α are the same)A. the value of the test statisticB. the p-valueC. both A. and B.D. the sign of the alternative is always =, andtherefore, cannot changeE. None of the above are correct.5. We want to investigate the relationship betweenhigh school grade point and college grade pointfor all Stat303 students this semester. Whattype of test should do perform (assuming thenecessary assumptions are met)?A. χ2testB. Linear RegressionC. ANOVAD. paired t-testE. two sample z-test for proportions2STAT302: 508-510 Exam #3, Form A Fall 2003Analysis of VarianceSource SS df MS F Prob > F---------------------------------------------------Btween grps 1.9152113 3 .638404 3.32 0.0274Within grps 9.43046516 49 .192458---------------------------------------------------Total 11.3456765 52 .218186Test for equal variances:chi2(3)= 4.2899 Prob>chi2 = 0.2326. What should we say about the treatment (group)effect in the ANOVA table above. i.e., what isthe conclusion?A. There is only a 2.74% probability that theeffect exists.B. The effect is only 2.74% significant.C. The effect is significant at the 5 and 10%levels.D. There is a 23.3% probability that the effectexists.E. The effect is not significant.7. In reference to the ANOVA table above, we as-sume the variances within each group are equal.What is our estimate of this variance?A. We don’t assume the variances are equalsince the p-value is less than 0.10.B. 9.43C. 11.3D. 0.218E. 0.1928. A fast food franchiser is considering building arestaurant in a certain location. Based on fi-nancial anyalyses, a site is acceptable only if thenumber of pedestrians passing the location av-erages more than 100 per hour. The number ofpedestrians is normally distributed, and we canassume that the population standard deviationis known to be 12. The number of pedestriansobserved for each of forty hours was recorded.Which type of statistical test should we employto decide if the site is acceptable?A. Case 10 since this test reduces the variabil-ity.B. Case 3 since the sample size is large (> 30)and we are testing one mean.C. Case 8 since we can assume that the vari-ances are both 122.D. Case 9 since we are not told that the vari-ances are equal.E. Case 1 since the population standard devia-tion is known and we are testing one mean.9. Say the p-value for the test above is 0.084. Whatis the best interpretation of this p-value?A. 84% of the time we will see at least 100pedestrians per hour when the true numberis less.B. 8.4% of the time we will reject H0eventhough it is a true statement.C. 8.4% of the time we will get a sample resultat least as large as our sample even thoughthe true amount is less than 100.D. 8.4% of the time we will get a sample resultas small as our sample even though the trueamount is more than 100.E. 84% of the time we will get a sample resultat least as large as our sample even thoughthe true amount is less than 100.Protein content: 15, 22, 17, 19, 2310. A group of nutritionists is hoping to prove thata new soy bean compound has more protein pergram than roast beef, which has a mean proteincontent of 20. A random sample of 5 batches ofthe soy bean compound have been tested, withthe results shown above. What assumption(s)do we have to make in order to carry out a legit-imate statistical test of the nutritionists’ claim?A. The observations are from a normally dis-tributed population.B. The


View Full Document

TAMU STAT 303 - ex3af03

Download ex3af03
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view ex3af03 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view ex3af03 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?