Final Exam free essay sample

As a result of this sample, it can be concluded that the average age of all the students at City College A. must be more than 22, since the population is always larger than the sample B. must be less than 22, since the sample is only a part of the population C. could not be 22 D. could be larger, smaller, or equal to 22 Since a sample is a subset of the population, the sample mean A. is always smaller than the mean of the population B. is always larger than the mean of the population C. must be equal to the mean of the population D. can be larger, smaller, or equal to the mean of the population Use the ollowing situation for Questions 4-7. We will write a custom essay sample on Final Exam or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Michael, Inc. , a manufacturer of electric defibrillators, is a firm that makes 50 types of electric defibrillators . The table below shows the price distribution of the defibrillators . Price (In $) Number of Defibrillators 100 – 130 8 140 170 12 180 210 20 220 250 10 Select from the following choices for Questions 4-7. Use letter only in the blank. A. 32 B. 50% C. 20 D. 30 E. 16% F. 10 G. 60% H. 50 How many defibrillators have a price of at least $180? _______ What percentage of the defibrillators has a price of at least $180? _____ What percentage of the defibrillators has a price of less than $140? _____ How many defibrillators cost at least $140 but no more than $210? ______ Temperature is an example of A. a qualitative variable B. a quantitative variable C. either a quantitative or qualitative variable D. neither a quantitative nor qualitative variable Use the following situation for Questions 9 and 10. The following frequency distribution shows the frequency of outb reaks of the ? 1? 1 virus (statistics flu) for the following households in a small rural community. 9. 10. 11. 12. 13. 14. Households 1134 406 168 41 25 12 Outbreaks 0 1 2 345 Use the frequency distribution to construct a probability distribution by filling in the blanks below. 0 1 2 3 4 5 x P(x) P(0) = __ P(1) = __ P(2) = __ P(3) = ___ P(4) = ___ P(5) = ___ Compute the mean and the standard deviation and select from the following the appropriate interpretation of the results (select best response) A. A household on the average has 0. 9 outbreaks with a standard deviation of . 6 outbreaks B. A household on the average has 0. 6 outbreaks with a standard deviation of 12 outbreaks C. A household on the average has 0. 9 outbreaks with a standard deviation of . 9 outbreaks D. A household on the average has 0. outbreaks with a standard deviation of .9 outbreaks Use the following situation for Questions 11 13. Twenty students were randomly selected for cholesterol screening. The following data were collected. 260 164 210 225 244 254 233 184 269 206 158 209 221 213 198 179 214 257 246 221 Using the information above compute the following: (Round to nearest hundre dth) A. Mean = _____ B. Median = _____ C. Mode = _____ D. Sample Standard Deviation = _____ E. The Sample Variance = ______ F. The Coefficient of Variation = ______ (as a percent, for example 27. 43%) Is the data skewed _______ (select correct letter from list below) A. No B. Skewed left C. Skewed right D. Unable to determine Which is the best measure of central tendency for the randomly selected cholesterol screenings? _______ (select correct letter from list below) A. Mean B. Median C. Mode D. It does not matter, one is as good as the other Let event A = a patient does not survive a new treatment procedure for prostrate cancer and event B = the patient is permanently rendered sexually dysfunctional by the new treatment. Furthermore, events A and B are mutually exclusive. Which of the following statements is also true? A. A and B are also independent. B. P(A or B) = P(A)P(B) C. P(A or B) = P(A) + P(B) D. P(A and B) = P(A) + P(B) 15. Twenty-five percent of the employees of a large hospital are minorities. A random sample of 7 employees is selected. A. B. C. D. E. 16. What is the probability that the sample contains exactly 4 minorities? ____ What is the probability that the sample contains fewer than 2 minorities? ____ What is the probability that the sample contains exactly 1 non-minority? ____ What is the expected number of minorities in the sample? ______ What is the variance of the minorities? _______ Select from the answers below. Place the correct letter in the blanks above. A. 0. 5551 B. 1. 1456 C. 0. 4449 D. 0. 0013 E. 1. 7226 F. 1. 3125 G. 0. 0577 H. .0001 I. 1. 75 J. 0. 0286 The life expectancy of a lung cancer patient treated with a new drug is normally distributed with a mean of 4 years and a standard deviation of 10 months. A. What is the probability that a randomly selected lung cancer patient will last more than 5 years? _____ B. What percentage of lung cancer patients will last between 5 and 6 years? ____ C. What percentage of lung cancer patients will last less than 4 years? _____ D. What percentage of lung cancer patients will last between 2. 5 and 4. 5 years? _ E. If the drug manufacturer guarantees the drug will be effective for a minimum of 3 years (and will pay for the entire treatment program if the patient does not survive), what percentage of lung cancer patients will have to pay for the treatment? _____ 17. Select from the answers below. Place the correct letter in the blanks above. A. 10. 69% B. 11. 51% C. .0796 D. 46. 01% E. 88. 49% F. 68. 9% G. 53. 98% H. 0% I. 50% J. 0. 06172 The life expectancy in the United States is 75 with a standard deviation of 7 years. A random sample of 49 individuals is selected. A. B. C. D. E. F. 18. What is the standard error of the mean? ____ What is the probability that the sample mean will be larger than 77 years? ___ What is the probability that the sample mean will be less than 72. 7 years? ___ What is the probability that the sample mean will be between 73. 5 and 76 years? _____ What is the probability that the sample mean will be between 72 and 74 years? _____ What is the probability that the sampl e mean will be larger than 73. 46 years? _____ Select from the answers below. Place the correct letter in the blanks above. A. 0. 0107 B. 0. 7745 C. 1. 0 D. 0. 8427 E. 0. 9772 F. 0. 0228 G. 1/7 H. 0. 9389 I. 22. 55% J. 0. 1573 The standard hemoglobin reading for healthy adult men is 15 g/110 ml with a standard deviation of ? = 2 g. For a group of men, we find a mean hemoglobin of 16. 0 g. A. Obtain a 95% confidence interval for if the group size was 25_____ B. Obtain a 95% confidence interval for if the group size was 36_____ C. Obtain a 95% confidence interval for if the group size was 49_____ Select from the answers below. Place the correct letter in the blanks above. A. 15. 440 16. 560 B. 15. 347 16. 653 C. 14. 440 15. 560 D. 14. 316 15. 684 E. 15. 316– 16. 684 F. 14. 347 15. 653 19. 20. Doubling the size of the sample will A. reduce the standard error of the mean to one-half its current value B. reduce the standard error of the mean to approximately 70% of its current value C. have no effect on the standard error of the mean D. double the standard error of the mean The fact that the sampling distribution of sample means can be approximated by a normal probability distribution whenever the sample size is large is based on the A. central limit theorem B. fact that we have tables of areas for the normal distribution C. assumption that the population has a normal distribution D. None of these alternatives is correct. Use the following situation for Questions 21 23. In order to estimate the average time spent on the dialysis machines per kidney patient at a local university hospital, data were collected for a sample of 81 patients over a one week period. Assume the population standard deviation is 1. 2 hours. 21. The standard error of the mean is 22. A. 7. 5 B. 0. 014 C. 0. 160 D. 0. 133 With a 0. 95 probability, the margin of error is approximately 23. A. 0. 26 B. 1. 96 C. 0. 21 D. 1. 64 If the sample mean is 9 hours, then the 95% confidence interval is 24. 25. 26. A. 7. 04 to 110. 96 hours B. 7. 36 to 10. 64 hours C. 7. 80 to 10. 0 hours D. 8. 74 to 9. 26 hours The t distribution is applicable whenever: A. the sample is considered large (n ? 30). B. the population is normal and the sample standard deviation is used to estimate the population standard deviation C. n ? 100 D. n ? 1000 Use the following situation for Questions 25 – 26. A random sample of 16 statistics examinations from a la rge population was taken. The average score in the sample was 78. 6 with a variance of 64. We are interested in determining whether the average grade of the population is significantly more than 75. Assume the distribution of the population of grades is normal. The test statistic is: A. 0. 45 B. 1. 80 C. 3. 6 D. 8 At 95% confidence, it can be concluded that the average grade of the population A. is not significantly greater than 75 B. is significantly greater than 75 C. is not significantly greater than 78. 6 D. is significantly greater than 78. 6 27. Independent samples are obtained from two normal populations with equal variances in order to construct a confidence interval estimate for the difference between the population means. If the first sample contains 16 items and the second sample contains 36 items, the correct form to use for the sampling distribution is the A. normal distribution B. t distribution with 15 degrees of freedom C. t distribution with 35 degrees of freedom D. t distribution with 50 degrees of freedom Use the following situation for Questions 28 – 33. A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following results. Mean Variance Sample Size 28. 29. 30. 31. 32. 33. Today 82 112. 5 45 Five Years Ago 88 54 36 The difference between the means of the two populations is (d ) = A. 58. 5 B. 9 C. -9 D. -6 The standard deviation of the difference between the means of the two populations is A. 12. 9 B. 9. 3 C. 4 D. 2 The 95% confidence interval for the difference between the two population means is A. -9. 92 to -2. 08 B. -3. 92 to 3. 92 C. -13. 84 to 1. 84 D. -24. 228 to 12. 23 The test statistic for the difference between the two population means is A. -. 47 B. -. 65 C. -1. 5 D. -3 The p-value for the difference between the two population means is A. .0014 B. .0028 C. .4986 D. 9972 What is the conclusion that can be reached about the difference in the average final examination scores between the two classes? (Use a . 05 level of significance. ) A. There is a statistically significant difference in the average final examination scores between the two classes. B. There is no statistically significant difference in the average final examination scores between the two classes . C. It is impossible to make a decision on the basis of the information given. D. There is a difference, but it is not significant. Use the following situation for Questions 34 – 38. The director of a regional hospital is interested in determining whether or not the proportion of incoming female patients who needs a pap-smear has increased. A sample of female patients taken several years ago is compared with a sample of female patients this year. Results are summarized below. Sample Size No. Requiring Pap-Smear 34. 35. 36. 37. 38. 39. 40. Previous Sample 250 50 Present Sample 300 69 The difference between the two proportions is: A. 50 B. 19 C. 0. 50 D. 0. 03 The pooled proportion has a value of A. 0. 216 B. 0. 216 C. 1. 645 D. 0. 5 The interest of the director represents a A. one tailed test B. wo tailed test C. one tailed or a two tailed test, depending on the confidence coefficient D. one tailed or a two tailed test, depending on the level of significance The test statistics for this test is A. 1. 645 B. 1. 96 C. 0. 035 D. 0. 851 If the test is to be done with an ? =. 05 the A. null hypothesis should be rejected B. null hypothesis should not be rejected C. a lternative hypothesis should be accepted D. None of these alternatives is correct. Regression analysis was applied between demand for a product (Y) and the price of the product (X), and the following estimated regression equation was obtained. Y = 120 10 X Based on the above estimated regression equation, if price is increased by 2 units, then demand is expected to A. increase by 120 units B. increase by 100 units C. increase by 20 units D. decease by 20 units If there is a very strong correlation between two variables, then the coefficient of correlation must be A. much larger than 1, if the correlation is positive B. much smaller than 1, if the correlation is negative C. much larger than one D. None of these alternatives is correct. 41. 42. 43. 44. 45. 46. 47. Regression analysis was applied between sales (in $1000) and advertising (in $100) and the following regression function was obtained. Y = 500 + 4 X Based on the above estimated regression line if advertising is $10,000, then the point estimate for sales (in dollars) is A. $900 B. $900,000 C. $40,500 D. $505,000 Use the following situation for Questions 42 – 46. You are given the following information about y and x. y x Dependent Variable Independent Variable 5 15 7 12 9 10 11 7 The least squares estimate of b1 equals A. -0. 7647 B. -0. 13 C. 21. 4 D. 16. 412 The least squares estimate of b0 equals A. -0. 7647 B. -1. 3 C. 164. 1176 D. 16. 41176 The sample correlation coefficient equals A. -86. 667 B. -0. 99705 C. 0. 9941 D. 0. 99705 The coefficient of determination equals A. -0. 99705 B. -0. 9941 C. 0. 9941 D. 0. 99705 A researcher selected a sample of 50 residents from each of three different cities to determine if they were willing to participate in a medical experiment. At ? = . 05, test the claim that the proportions who will participate are equal. Residents City 1 City 2 City 3 Willing to participate 20 12 22 Not willing to participate 30 38 28 Total 50 50 50 A. There is not evidence to reject the claim that the proportions are equal because the test value 4. 861 lt; 5. 991 B. There is evidence to reject the claim that the proportions are equal because the test value gt; 1. 42 C. There is not evidence to reject the claim that the proportions are equal because the test value 5. 991lt; 12. 592 D. There is evidence to reject the claim that the proportions are equal because the test value 5. 991 gt; 1. 042 A researcher is comparing samples from 6 different populations. Assume that the conclusion from an ANOVA is that the null hypothesis is rejected, in other words that the 6 population means are not all equal. How many of the population means would be significantly different from the others? A. Three (half) B. At least 1 C. All would be different D. More than 2 Use the following situation for Questions 48 – 50. A research firm reported that 15% of those surveyed described their health as poor, 26% as good, 40% as very good, and 19% as excellent. A health professional in Chicago wanted to determine if people in Chicago had similar feelings toward their health. In a sample of 600 people in Chicago, 70 described their health as poor, 180 as good, 210 as very good, and 140 as excellent. Complete the chart below by filling in the observed and expected values. 48. 49. 50. Observed Expected Poor Good Very Good Excellent Calculate the test statistic ________ (to two decimal places, i. 2. 34) Given an ? = . 05, what is the result of the chi-squared test? A. There is not evidence to reject the claim that the proportions are equal because the test value is less than the critical ? 2 value. B. There is evidence to reject the claim that the proportions are equal because the test value is greater than the critical ? 2 value. C. There is not eviden ce to reject the claim that the proportions are equal because the test value is greater than the critical ? 2 value. D. There is evidence to reject the claim that the proportions are equal because the test value is less than the critical ? 2 value.

Syncra Systems essays

Syncra Systems essays According to a 1996 study, retail product stock-outs in the industry occur at an average rate of 8.2%. The stock-outs led to lose of sales and customer dissatisfaction, and then eventually affected the profit margin of retailers and manufacturers significantly. The traditional answer to addressing customer service problems has been to increase inventories. But high inventory means high cost. From the retailers side, the more unpredictable demand is the more inventory is required to manage the risk. From the suppliers side, the uncertainty of supply processes creates problems for inventory management. Effectively managing inventory buffers and supply process variability can reduce the need for inventory. Inventory reductions in the supply chain should also be expected to reduce operating costs. Collaborative Planning Forecasting and Replenishment (CPFR) is a set of norms and procedures created by the Voluntary Interindustry Commerce Standards Association (VICS), driving companies towards common business planning procedures, and searching for higher efficiency in the supply chain by establishing standards to facilitate the physical and informational flow. CPFR allows buyers and sellers to collaborate in forecasting and ordering. Moreover, collaborative control also allows a better production and distribution planning so as to optimize the balance between cost and service. Using CPFR, value-chain participants can minimize inventories and focus on value-added process activities. E-commerce is at a crossroads. For many suppliers and distributors, EDI has become the backbone for computerized B-to-B communication. Meanwhile, Internet has brought universal access and has become a host of new technologies. The danger is that the benefits of electronic commerce standards such as EDI will be swept away by the excitement of the Internet, leading to potential incompatible practices among suppliers and distributors. CPFR intends ...