QMB 6406 - Final Exam (Latest) - Already Graded A+

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he median is often a better representative of the central value of a data set when the data set: Source Is bimodal. Has a high standard deviation. Is highly skewed. 2. The data in the Excel spreadshee... t linked below provide information on the nutritional content (in grams per serving) of some leading breakfast cereals. For which nutrients is the mean nutrient content per serving greater than the median nutrient content per serving? Breakfast Cereals Source Proteins only. Complex carbohydrates only. Both nutrients. Neither nutrient.
Has no outliers. 3. 3 The histogram below plots the carbon monoxide (CO) emissions (in pounds/minute) of 40 different airplane models at take-off. The distribution is best described as is: Source Uniform. Heteroskedastic. Normal. Skewed right. 4. 4. The histogram below plots the carbon monoxide (CO) emissions (in pounds/minute) of 40 different airplane models at take-off. Which of the following statements is the best inference that can be drawn from this histogram? Source The mean amount of carbon monoxide emissions is greater than the median amount of carbon monoxide emissions. The mean amount of carbon monoxide emissions is less than the median amount of carbon monoxide emissions. The mean and median amounts of carbon monoxide emissions are about equal. The relative sizes of the mean and median amounts of carbon monoxide emissions cannot be inferred from the histogram 5. In the data set shown below, the correlation coefficient of the two variables is: Correlation Data Source -1.0. -0.5 0.0 None of the above 6. The data in the Excel spreadsheet linked below give the ages and salaries of the chief executive officers of 59 companies with sales between $5 million and $350 million. The correlation between age and salary can be characterized as: CEO Salaries Source Strong and positive. Strong and negative. Weak and positive. Weak and negative. 7. For a given set of data, the standard deviation measures: Source The difference between the mean and the data point farthest from the mean. The difference between the mean and the data point nearest to the mean. The difference between the mean and the median. None of the above. 8. The data in the Excel spreadsheet linked below give the average exchange rates of four currencies to the US dollar during October 2002. Over this period, which currency was most volatile relative to the US dollar, as measured by the coefficient of variation? Exchange Rates Source The Brazilian Real. The Euro. The Japanese Yen. The South Korean Won. 9. A national business magazine intends to survey its subscribers to determine who they think is the "CEO of the Century." Subscribers are invited to complete an online survey. Based only on this information, which of the following can be inferred about the survey results? Source They will be biased because the magazine's subscribers are unqualified to determine who the CEO of the century is. They will accurately reflect the opinion of the nation as a whole about who the CEO of the century is. They will be unbiased because the respondents will be self-selected. They will be biased because subscribers who have access to the online survey are not representative of the population of subscribers as a whole. 10. A political consultant conducts a survey to determine what position the mayoral candidate she works for should take on a proposed smoking ban in restaurants. Which of the following survey questions will deliver an unbiased response? Source Should the city ban smoking in restaurants to protect our children from second-hand smoke? Should tobacco smoke, a known cause of lung cancer, be banned from public spaces such as restaurants? Does the city have the right to restrict recreational activities, such as moderate consumption of alcohol or tobacco, on the premises of privately-owned businesses? None of the above 11. In a recently administered IQ test, the scores were distributed normally, with mean 100 and standard deviation 15. What proportion of the test takers scored between 70 and 130? Source About 68%. About 84%. About 95%. About 99.5%. 12. Which of the following is not true about the Normal Distribution? Source It is symmetric. Its mean and median are equal. It is completely described by its mean and its standard deviation. It is bimodal. 13. The histogram below shows the underlying distribution pattern of the results of a rolled die. Suppose the die is rolled 50 times and the results are averaged. Suppose this process — rolling 50 dice and averaging their results — is repeated 100 times. Which of the following best describes the distribution of these 100 averages? Source Skewed right. Skewed left. Normal. Uniform. 14. A nutrition researcher wants to determine the mean fat content of hen's eggs. She collects a sample of 40 eggs. She calculates a mean fat content of 23 grams, with a sample standard deviation of 8 grams. From these statistics she calculates a 90% confidence interval of [20.9 grams, 25.1 grams]. What can the researcher do to decrease the width of the confidence interval? Source Increase the confidence level. Decrease the confidence level. Decrease the sample size None of the above 15. In a random sample of 321 senior citizens, 61 were found to own a home computer. Based on this sample, the 95% confidence interval for the proportion of computer-owners among senior citizens is: Source [2.6%; 7.4%]. [13.4%; 24.6%]. [14.7%; 23.3%]. The answer cannot be determined from the information given. 16. Preliminary estimates suggest that about 58% of students at a state university favor implementing an honor code. To obtain a 95% confidence interval for the proportion of all students at the university favoring the honor code, what is the minimum sample size needed if the total width of the confidence interval must be less than 5 percentage points (i.e., the confidence interval should extend at most 2.5 percentage points above and below the sample proportion)? Source 375. 264. 1,498. The answer cannot be determined from the information given. 17. In a survey of twelve Harbor Business School graduates, the mean starting salary was $93,000, with a standard deviation of $17,000. The 95% confidence interval for the average starting salary among all Harbor graduates is: Source [$83,382; $102,618]. [$82,727; $103,327]. [$82,199; $103,801]. [$59,000; $127,000]. 18. In a survey of 53 randomly selected patrons of a shopping mall, the mean amount of currency carried is $42, with a standard deviation of $78. What is the 95% confidence interval for the mean amount of currency carried by mall patrons? Source [$39.1; $44.9]. [$24.4; $59.6]. [$21.0; $63.0]. [$14.4; $69.6]. 19. A filling machine in a brewery is designed to fill bottles with 355 ml of hard cider. In practice, however, volumes vary slightly from bottle to bottle. In a sample of 49 bottles, the mean volume of cider is found to be 354 ml, with a standard deviation of 3.5 ml. At a significance level of 0.01, which conclusion can the brewer draw? Source The true mean volume of all bottles filled is 354 ml. The machine is not filling bottles to an average volume of 355 ml. There is not enough evidence to indicate that the machine is not filling bottles to an average volume of 355 ml. The machine is filling bottles to an average volume of 355 ml. 20. To conduct a one-sided hypothesis test of the claim that houses located on corner lots (corner-lot houses) have higher average selling prices than those located on non-corner lots, the following alternative hypothesis should be used: House Prices Data Source The average selling price of a corner-lot house is higher than it is commonly believed to be. The average selling price of a corner-lot house is higher than the average selling price of all houses. The average selling price of a corner-lot house is the same as the average selling price of a house not located on a corner lot. The average selling price of a corner-lot house is higher than the average selling price of a house not located on a corner lot. 21. The data in the Excel spreadsheet linked below indicate the selling prices of houses located on corner lots ("corner-lot houses") and of houses not located on corner lots. Conduct a one-sided hypothesis test of the claim that corner-lot houses have higher average selling prices than those located on non-corner lots. Using a 99% confidence level, which of the following statements do the data support? House Prices Data Source Upscale, expensive neighborhoods have more street corners. The average selling price of a corner-lot house is higher than that of the average house not located on a corner lot. The average selling price of a corner-lot house is no more than that of the average house not located on a corner lot. There is not enough evidence to support the claim that the average selling price of a corner-lot house is higher than that of the average house not located on a corner lot. 22. Two semiconductor factories are being compared to see if there is a difference in the average defect rates of the chips they produce. In the first factory, 250 chips are sampled. In the second factory, 350 chips are sampled. The proportions of defective chips are 4.0% and 6.0%, respectively. Using a confidence level of 95%, which of the following statements is supported by the data? Source There is not sufficient evidence to show a significant difference in the average defect rates of the two factories. There is a significant difference in the average defect rates of the two factories. The first factory's average defect rate is lower than the second factory's on 95 out of 100 days of operation. None of the above. 23. The regression analysis below relates average annual per capita beef consumption (in pounds) and the independent variable "average annual beef price" (in dollars per pound). The coefficient on beef price tells us that: Beef Consumption and Price Source For every price increase of $1, average beef consumption decreases by 9.31 pounds. For every price increase of $1, average beef consumption increases by 9.31 pounds. For every price increase $9.31, average beef consumption decreases by 1 pound. For price increase of $9.31, average beef consumption increases by 1 pound. 24. The regression analysis below relates average annual per capita beef consumption (in pounds) and the independent variable "average annual beef price" (in dollars per pound). In a year in which the average price of beef is at $3.51 per pound, we can expect average annual per capita beef consumption to be approximately: Beef Consumption and Price Source 55.2 pounds 52.6 pounds 53.6 pounds 117.9 pounds 25. The regression analysis below relates average annual per capita beef consumption (in pounds) and the independent variable "average annual per capita pork consumption" (in pounds). At what level is the coefficient of the independent variable pork consumption significant? Beef Consumption and Pork Consumption Source 0.10. 0.05. 0.01. None of the above. 26. The regression analysis below relates average annual per capita beef consumption (in pounds) and the independent variable "average annual per capita pork consumption" (in pounds). Which of the following statements is true? Beef Consumption and Pork Consumption Source Beef consumption can never be less than 65.09 pounds. Beef consumption can never be greater than 65.09 pounds. The y-intercept of the regression line is 65.09 pounds. The x-intercept of the regression line is 65.09 pounds. 27. The regression analysis at the bottom relates average annual per capita beef consumption (in pounds) and the independent variables "average annual per capita pork consumption" (in pounds) and "average annual beef price" (in dollars per pound). Which of the independent variables is significant at the 0.01 level? Beef Consumption, Pork Consumption, and Beef Price Source Beef price only. Pork consumption only. Both independent variables. Neither independent variable. 28. The regression analysis at the bottom relates average annual per capita beef consumption (in pounds) and the independent variables "annual per capita pork consumption" (in pounds) and "average annual beef price" (in dollars per pound). The coefficient for beef price, -12, tells us that: Beef Consumption, Pork Consumption, and Beef Price Source For every $1 increase in beef price, average beef consumption decreases by 12 lbs, not controlling for pork consumption. For every $12 drop in beef price, average beef consumption decreases by 1 lbs, not controlling for pork consumption. For every $1 increase in beef price, average beef consumption decreases by 12 lbs, controlling for pork consumption, i.e. holding pork consumption constant. For every $12 decrease in beef price, average beef consumption decreases by 1 lbs, controlling for pork consumption, i.e. holding pork consumption constant. 29. The data in the Excel spreadsheet linked below give the seasonally adjusted value of total new car sales (in millions of dollars) in the United States, total national wage and salary disbursements (referred to here as "compensation") (in billions of dollars), and the employment level in the non-agricultural sector (in thousands) for 44 consecutive quarters. An auto industry executive wants to know how well she can predict new car sales two quarters in advance using the current quarter's compensation data. How many data points can she use in a regression analysis using the data provided? [Show More]

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