7. The data in the Excel spreadsheet linked below gives the average monthly price of gold (in dollars per ounce) for the years 1980 to1983. Which of the following statistics measures gold price variation in the same units as gold price itself (i.e., dollars per ounce)? Gold Prices Source The standard deviation. The variance. The coefficient of variation. None of the above. 21. In a survey of 48 citizens, 36 registered strong disapproval with their government's economic leadership. In the previous month, the proportion of participants registering strong disapproval was 65%. At the 95% confidence level and using a two-sided test, which of the following statements do these data support? Source There is not sufficient evidence to indicate that the proportion of participants registering strong disapproval has changed. The proportion of participants registering strong disapproval has stayed the same. 22. The proportion of participants registering strong disapproval has increased. None of the above. A telemarketing company wants to find out if people are more likely to answer the phone between 8pm and 9pm than between 7pm and 8pm. Out of 96 calls between 7pm and 8pm, 72 were answered. Out of 105 calls between 8pm and 9pm, 90 were answered. Using a one-sided hypothesis test with a 90% confidence level, which of the following statements do these data support? Source There is not sufficient evidence that the proportion of people who answer the phone between 8pm and 9pm is greater than the proportion who answer the phone between 7pm and 8pm. People are more likely to answer the phone between 8pm and 9pm. Telemarketers should not call at all during the evenings. People are more likely to answer the phone between 7pm and 8pm. 23. The regression analysis below relates US annual energy consumption in trillions of BTUs to the independent variable "US Gross Domestic Product (GDP) in trillions of dollars." Which of the following is the lowest level at which the independent variable is significant? Energy Consumption and GDP Source 0.94 0.10 0.05 0.01 30. The data table below tabulates a pizza parlor's advertising expenditures and sales for 8 consecutive quarters. The marketing manager wants to know how much of an impact current advertising will have on sales two quarters from now. When running a regression with the dependent variable "sales" and the independent variable "advertising lagged by two quarters," how many data points can she use, given the available data? Pizza Parlor Sales and Advertising Source 6 7 8 9 31. In a regression analysis, a residual is defined as: Source The difference between the actual value and the predicted value of the dependent variable. The difference between the actual value and the predicted value of the independent variable. The proportion of the variation in the independent variable that remains unexplained by the variation in the dependent variable. The proportion of the variation in the dependent variable that remains unexplained by the variation in the independent variable. 33. Amalgamated Fruits, Vegetables, and Legumes, an agricultural company, breeds the experimental fruit "kiwana." The company is studying the effects of a new fertilizer on the number of kiwanas per bunch grown on kiwana trees. The regression analysis below relates the number of kiwanas per bunch to the independent dummy variable "fertilizer." Based on the regression, which of the following statements may be concluded? Kiwana Growth and Fertilizer Source On average, the use of the new fertilizer increases the number of kiwanas per bunch by 5.25. The independent dummy variable "fertilizer" is significant at the 0.01 level. Variation in the independent dummy variable "fertilizer" explains around 53% of the variation in the number of kiwanas per bunch. None of the above. 35. Market researcher Ally Nathan is studying the relationships among price, type (classical or steel string), and consumer demand for acoustic guitars. She wants to find the relationship between demand and price, controlling for type. To determine this relationship, she should: Source Run a simple regression of the dependent variable demand on the independent variable price and observe the coefficient on price. Run a simple regression of the dependent variable demand on the independent variable type and observe the coefficient on type. Run a multiple regression of the dependent variable demand on the independent variables price and type and observe the coefficient on price. Run a multiple regression of the dependent variable demand on the independent variables price and type and observe the coefficient on type. 37. The table below displays data on defect rates at a compact disk (CD) pressing facility. The table includes data on the distribution of CDs that have content errors (missing and/or wrong content), and on the distribution of CDs that have labeling errors. What is the conditional probability that a CD has no content errors, given that has a labeling error? Source 97.02% 1.98% 98.00% None of the above