Download Statistics: Confidence Intervals and Hypothesis Testing and more Schemes and Mind Maps Probability and Statistics in PDF only on Docsity! Name Iÿ,G l Period + Sections lO.land 10.2 Review ÿ' Answer all questions on a separate sheet of paper. Do NOT turn in this sheet. Please be sure to keep a copy of the answers to check on Thursday. Multiple Choice. . A confidence interval estimate is determined from the GPAs of a simple random sample of n students. Which of the following will result in a smaller margin of error? I. A smaller confidence level II. A smaller standard deviation III. A smaller sample size (++t++!>'ÿ,ÿ.ÿIÿ ÿ';ÿ +ÿ+,' ÿ+++ÿ,ÿ,+<++ÿ,++ ,r ÿv,ÿ+ÿ,+ÿ, ++ÿ+)+ (IAÿ I and II (B) I and III (C) II and III (D) I, II, and III (E) None of the above gives the complete set of true responses. , One month the actual unemployment rate in France was 13.4%. If during that month you took an SRS of 100 Frenchmen and constructed a confidence interval estimate of the unemployment rate, which of the following would be true? .... Iÿ The center of the interval was 13.4. +I+lÿ." The interval contained 13.4. .IZI. A 99% confidence interval estimate contained 13.4. (A) I and II (B) I and III (C) II and III (D) I, II and III O None of the above the set of truegives complete responses. , The margin of error in a confidence interval estimate using z-scores covers which of the following? I. Random sampling errors l II. Errors due to undercoverage and nonresponse in obtaining sample surveys (ÿ/,,ÿ,+ÿ ,,ÿ,ÿ+,,ÿ, ÿiÿ ,,ÿ ÿ ) III. Errors due to using sample standard deviations as estimates for population standard deviations I only (B) II only (C) III only (D) I and III (E) None of the above gives the complete set of true responses. , The number of accidents per day at a large factory is noted for each of 64 days with x = 3.58 and s = 1.52. Assuming that "s" is a reliable estimate for the population standard deviation, with what degree of confidence can we assert that the mean number of accidents per day at the factory is between 3.2076 and 3.9524? 1,3ÿ. ÿ ÿ ÿ ÿ ÿl (A) 48 70 ,iÿ(jiÿ ...... ............ (8) 63% (c) 907o, @ 957o .... ..... ' (E) 99% ÿ:ÿ' ÿ, l,(I I,ÿ , What sample size should be chosen to find the mean number of absences per month for school children to within +.:2 at a 95% confidence level if it is known that the standard deviation is 1.1? (B) ii (C) 82 (b) I16 l l'l (ÿ 117 , Which of the following are true statements? I. The P-value of a test is the probability of obtaining a result as extreme as the one obtained assuming that the null hypothesis is true. II. If the P-value for a test is .015, the probability that the null hypothesis is true is .015. III. When the null hypothesis is rejected, it is because it is not true. I only (B) II only (C) III only (D) I and III (E) None of the above gives the complete set of true responses. , Which of the following are true statements? I. Tests of significance (hypothesis tests) are designed to measure the strength of evidence against the null hypothesis. II1 A well-planned test of significance should result in a statement either that the null hypothesis is true or that it is fa!ÿ,e, III. The alternative hypothesis is one-sided if there is interest in deviations from the null hypothesis in only one direction. (A) I and II I and III (C) II and III (D) I, II and III (E) None of the above gives the complete set of true responses.
