1、第 頁2021知到答案【 商務統計冬學期 智慧樹滿 分章節測試答案 第一章 章節測試第三章 章節測試t-table答案: 【do not reject the null hypothesis】 7、選擇題: Stefan Irwin, Marketing Manager at Classic Merchandise, is investigating response rates to scented and unscented direct mail catalogues. If the response rate for the scented catalogue (population

2、1) is higher, Mike will adopt the scented version. His staff randomly selects two samples of 200 each from the companys customer database. One month after the 400 test catalogues were mailed, forty-five orders (twenty-five from the scented and twenty from the unscented) were received from the test c

3、atalogues. Assuming a = .01, Mikes alternate hypothesis is _. 選項：A:p1 p2 0B:m1 m2= 0C:m1 2 0D:s12 s22答案: 【p1 p2 0】 8、選擇題: Cowra Construction Company purchases steel rods for its projects. Based on previous tests, Clarrie Carter, Quality Assurance Manager, has recommended purchasing rods from Redding

4、 Rods (population 1), rather than Stockton Steel (population 2), since Reddings rods had less variability in length. Recently, Stockton revised it rod shearing operation, and Clarrie has sampled the outputs from Reddings and Stocktons rod manufacturing processes. The results for Redding were s12= 0.

5、10 with n1= 8, and, for Stockton, the results were s22= 0.05 with n2= 10. Assume that rod lengths are normally distributed in the population. Clarries alternate hypothesis is _. 選項：A:s12 = s22B:s12 s22C:s12 s22D:s12 s22答案: 【s12 s22】 9、選擇題: Tamara Hill, Fund Manager with Hillcrest Value Fund, manages

6、 a portfolio of 250 common stocks. Tamara is searching for a low risk issue to add to the portfolio, i.e. one with a price variance less than that of the SP 500 index. Moreover, she assumes an issue is not low risk until demonstrated otherwise. Her staff reported that during the last nine quarters t

7、he price variance for the SP 500 index (population 1) was 25, and for the last seven quarters the price variance for XYC common (population 2) was 8. Assume that stock prices are normally distributed in the population. Using a = 0.05, the appropriate decision is _. 選項：A:do not reject the null hypoth

8、esis s12 s22B:eject the null hypothesis s12 s22C:reject the null hypothesis s12 = s22D:do not reject the null hypothesis s12 = s22答案: 【do not reject the null hypothesis s12 = s22】 10、選擇題: Cindy Ho, Finance Manager at Red Hill Radiator Supplies (RHRS), theorises that the discount level offered to cre

9、dit customers affects the average collection period on credit sales. Accordingly, she has designed an experiment to test her theory using four sales discount rates (0%, 2%, 4% and 6%) by randomly assigning five customers to each sales discount rate. An analysis of Cindys data produced the following

10、ANOVA table. Source of Variation SS df MS F Treatment 5.35 3 1.783333 Error 177.2 16 11.075 Total 182.55 19 Using a= 0.01, the appropriate decision is _.選項：A:do not reject the null hypothesis m1= m2= m3= m4B:reject the null hypothesis m1 m2 m3 m4C:do not reject the null hypothesis m1 m2 m3m4D:reject

11、 the null hypothesis m1= m2= m3= m4答案: 【do not reject the null hypothesis m1= m2= m3= m4】第十一章 章節測試 1、選擇題: For the same set of observations on a specified dependent variable, two different independent variables were used to develop 2 simple linear regression models. The results are summarized as foll

12、ows: Based on the above results, we can conclude that選項：A:the SSE for Model II is smaller than the SSE for Model I.B:a prediction based on Model II is likely better than a prediction based on Model I.C:a prediction based on Model I is likely better than a prediction based on Model II.D:the total var

13、iation is different for Model I and Model II.答案: 【a prediction based on Model I is likely better than a prediction based on Model II.】 2、選擇題: A regression analysis between sales (in $1000) and advertising (in $100) yielded the least squares line = 75 + 6x. This implies that if $800 is spent on adver

14、tising, then the predicted amount of sales (in dollars) is選項：A:$4,875B:$487,500C:$123,000D:$12,300答案: 【$123,000】 3、選擇題: The following results were obtained from a simple regression analysis: = 37.2895 1.2024x r2= 0.6744 and s2= 0.2934 For each unit change in x, the estimated change in the averageval

15、ue of yis equal to選項：A:0.6744B:37.289C:0.2934D:-1.2024答案: 【-1.2024】 4、選擇題: A regression analysis between sales (in $1,000) and advertising (in $) yielded the least square line = 80,000 + 5x This implies that an選項：A:increase of $1 in advertising is expected to result in an increase of $5,000 in sales

16、.B:increase of $1 in advertising is expected to result in an increase of $5 in sales.C:increase of $5 in advertising is expected to result in an increase of $5,000 in sales.D:increase of $1 in advertising is expected to result in an increase of $80,005 in sales.答案: 【increase of $1 in advertising is

17、expected to result in an increase of $5,000 in sales.】 5、選擇題: The point estimate of the variance of the error term in a regression model is選項：A:SSEB:C:D:MSE答案: 【MSE】 6、選擇題: In a regression problem, if the coefficient of determination is 0.95, this means that:選項：A:95% of the variation in x can be exp

18、lained by the variation in y.B:95% of the y values are positive.C:95% of the variation in y can be explained by the variation in x.D:95% of the x values are equal.答案: 【95% of the variation in y can be explained by the variation in x.】 7、選擇題: In regression analysis, the residuals represent the:選項：A:change in y per unit change in x.B:difference between the actual y values and their predicted values.C:square root of the coefficient of determination.D:difference between the actual x values and their predicted values.答案: 【difference between the actual y values and th