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Res 342 final exam answersDocument Transcript

• http://universityofphoenixpaper.blogspot.com/ Page 1 of 14 Res 342 - Final Exam You can get your own complete guide from http://bit.ly/res-342 A + Tutorial Guaranteed 1) What are the critical z-values for a two-tailed hypothesis test if the significant level = 0.01? A. ± 2.58 B. ± 1.65 C. ± 2.33 D. ± 1.96 2) The area of rejection, on a bell shaped curve, defines the location of all those values that are A. so small or so large that the probability of their occurrence under a true null hypothesis is rather slim B. so small or so large that the probability of their occurrence under a true null hypothesis is to be expected C. within the selected confidence interval for the test D. so small or so large that the probability of their occurrence under a false null hypothesis is rather remote You can get your own complete guide from http://bit.ly/res-342 3) A hypothesis test that involves a small sample requires that we make the following assumption that A. the population is normally distributed B. the region of acceptance will be wider than for large samples C. a larger computed value of t will be needed to reject the null hypothesis D. the confidence interval will be wider than for large samples
• http://universityofphoenixpaper.blogspot.com/ Page 2 of 14 4) A statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test she wished to perform might have unacceptable large possibilities of Type II error, ß. Which of the following would solve this problem? A. Convince upper management to reduce the level of significance of the test. B. Convince upper management to use a smaller p-value. C. Convince upper management to use a larger sample. D. Convince upper management to use a larger p-value. 5) K & S Construction, located in Phoenix, Arizona, is working on its business plan for the upcoming year. They did a study to determine if they should focus on building condominiums or individual houses. A building study, which had been conducted by the state, indicated that 60 percent of those families looking to buy a home in Arizona desired to buy a condominium. K & S Construction wanted to know if this figure applied to Phoenix. They collected a sample of 500 individuals that had expressed plans to buy a new home. The z-distribution was selected for this proportion test. The null hypothesis is p = 0.60 and the alternate is p ≠ 0.60. The significant level selected was .05. From the sample of 500, it was determined that 290 wanted to buy a condominium. What decision should be made regarding the null hypothesis? A. Reject it B. The test level of .05 is not acceptable C. Cannot accept nor reject it based on the information given D. Fail to reject it 6) Doi Winery has two wine shops in the neighboring towns of Seamen and Batavia. The favorite wine, as advertised, is Raspberry wine. A survey of 300 customers at the Seamen store revealed that 225 individuals preferred the Raspberry wine while 290 out of 400 in Batavia preferred the same flavor. To test the hypothesis that there was no difference in preferences in the two towns, what is the alternate hypothesis? A. µ1 > µ2 B. µ1 = µ2 C. µ1 ≠ µ2 D. µ1 < µ2 7) A machine is set to fill the small size packages of Good and Better candies are packaged with 60 pieces of candies in each bag. Sampling results revealed: 3 bags of 61, 2 bags of 59, 1 bag of 58, and 2 bags of 62. How many degrees of freedom are there? A. 9 B. 7 C. 1 D. 8
• http://universityofphoenixpaper.blogspot.com/ Page 3 of 14 8) Thomas Delivery has a fleet of 24 trucks that are utilized for the companies; business. Electro-Lite, a manufacturer of spark plugs, claims that its spark plugs have an average life in excess of 25,000 miles. The purchasing agent at Thomas Delivery purchased 24 sets and found that the sample average life was 26,300 miles, the sample standard deviation was 1,500 miles, and the computed test statistic was t = 3.423. Based on these findings, at the 0.05 level, is there enough evidence to accept the manufacturer's claim? A. Electro-Lite claims are not supported by the test results. B. Electro-Lite claims are just an advertising promotion. C. Electro-Lite claims cannot be supported or denied with the test results. D. Electro-Lite claims are supported; the spark plugs do exceed the mean of 25,000 miles. 9) You are conducting a two-tailed test of means but your software package only calculates a one-tailed p-value equal to 0.13. The actual p-value for your test is A. You need a table to calculate this value. B. 0.26. C. 0.065. D. 0.13. 10) Golf balls that are properly manufactured will have a rebound height of 42 inches when dropped by a testing machine from a height of 5 feet. The quality control inspector is concerned that a new manufacturing machine is not properly calibrated and that the resulting golf balls are falling short of the desired height. At random, 100 golf balls were selected for a test. The test results indicated that the rebound height was 41.6 inches with a standard deviation of 0.5. At the .05 significant level, what is the result of the test? A. A larger test sample is needed. B. There is a significant difference; the golf balls are defected. C. There is no significant difference. D. A decision regarding a significant difference cannot be made. 11) Flash Jolt, a manufacturer of camera equipment, annually introduces new models in the fall of the year. At the conclusion of the Christmas season, retail dealers are contacted regarding their stock on hand of each piece of equipment. It has been discovered that unless 47% of the new equipment ordered by the retailers in the fall had been sold by Christmas, immediate production cutbacks are needed. At the end of the 2009 Christmas shopping season a survey of 100 dealers indicated that 45% of Flash Jolt equipment had been sold. It was decided to continue production levels at the current levels. The statistical test was conducted at the 0.05 level. Computed z = –0.40. A. The two percentage points be attributed to sampling error B. Wrong decision, should have cut back production C. Cannot determine based on information given D. Correct decision, not a significant difference 12) In a test for the equality of two variances (two-tailed), when the populations are normal, a 5% level of significance was used. Sample sizes were n1 = 13 and n2 = 10. The upper critical value for the test is
• http://universityofphoenixpaper.blogspot.com/ Page 4 of 14 A. =FINV(0.05, 12, 9). B. =FINV(1-0.025, 13, 10). C. =FINV(0.025, 12, 9). D. =FINV(0.025, 13, 10). 13) The owner of a bottling company is considering buying a new bottling machine. He has been testing two different machines that are being considered. After collecting 300 samples from each machine over several weeks, he was able to conduct a two sample z test.<p>He decided to utilize a 0.05 significant level for the test. The test was to address the claim that the mean weight of the bottles filled by the Orno machine was greater than the mean weight of the bottles filled by the Edne machine. The test statistics was 2.21. What is the decision regarding the hypothesis? A. This is a two tail test and the critical value for the test is 1.96. B. Reject the null hypothesis; there is a significant difference. C. There is not enough data available to answer the question. D. Accept the null hypothesis; there is not a significant difference. 14) Accounting procedures allow a business to evaluate their inventory at LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in \$ thousands) for five products both ways. Based on the following results, is LIFO more effective in keeping the value of his inventory lower? Product FIFO (F) LIFO (L) 1 225 221 2 119 100 3 100 113 4 212 200 5 248 245 The 5% level of significance was selected for the t value. This example is what type of test? A. Test of proportions. B. Two sample test of means. C. One sample test of means. D. Paired t-test. 15) Indy H2O is a water bottling company. They are looking at two different bottling manufacturers’ equipment for the purpose of replacing some old equipment. The net weights of a sample of bottles filled by a machine manufactured by WTR, and the net weights of a sample filled by a similar machine manufactured by Target are (in grams): WTR: 8, 9, 7, 8, 9, and 10 Target: 8, 10, 7, 11, 9, 12, 8, and 9 Testing the claim at the 0.05 level that the mean weight of the bottles filled by the Target machine is greater than the mean weight of the bottles filled by the WTR machine, what is the critical value? A. 2.145
• http://universityofphoenixpaper.blogspot.com/ Page 5 of 14 B. 2.179 C. 1.782 D. 1.632 16) A consumer researcher is testing the difference between two proportions at the 0.05 level of significance. The researcher was utilizing the z distribution for the test. If the computed test statistic z value was 1.12, what was the decision? A. Reserve judgment. B. Do not reject the null hypothesis. C. Reject the null hypothesis. D. Take a larger sample. 17) Two different accounting procedures that are utilized by businesses as a way to evaluate their inventory are LIFO (Last In First Out) and FIFO (First In First Out). ABC manufacturer evaluated its finished goods inventory (in \$ thousands) for five products using both procedures. Based on the following results, is LIFO more effective in keeping the value of his inventory lower? Product FIFO (F) LIFO (L) 1 225 221 2 119 100 3 100 113 4 212 200 5 248 245 The 5% level of significance was selected for the t value. The calculated test statistic was 1.93. What is the decision? A. Reject the null hypothesis and conclude LIFO is more effective. B. Fail to reject the null hypothesis and conclude LIFO is not more effective. C. Fail to reject the null hypothesis and conclude LIFO is more effective. D. Reject the alternate hypothesis and conclude LIFO is more effective. 18) If the paired differences are normal in a test of mean differences, the distribution used for testing is the A.normal distribution. B. student t distribution. C. F distribution. D. chi-square. 19) Watson's TV claims that their televisions have the best performance record on the market. They advertise that after 3 years only 10% of their sold televisions have had any type of repairs. The president of the company wanted to confirm that this statement was correct. To do this, a sample of 60 sets was taken of sets that had been sold and were at least 3 years old. Twelve percent of these television sets had been in for repair. The null hypothesis is that there is no