Exam 11: Analysis of Variance

TABLE 11-8 A physician and president of a Tampa Health Maintenance Organization (HMO)are attempting to show the benefits of managed health care to an insurance company.The physician believes that certain types of doctors are more cost-effective than others.One theory is that Primary Specialty is an important factor in measuring the cost-effectiveness of physicians.To investigate this,the president obtained independent random samples of 20 HMO physicians from each of 4 primary specialties - General Practice (GP),Internal Medicine (IM),Pediatrics (PED),and Family Physicians (FP)- and recorded the total charges per member per month for each.A second factor which the president believes influences total charges per member per month is whether the doctor is a foreign or USA medical school graduate.The president theorizes that foreign graduates will have higher mean charges than USA graduates.To investigate this,the president also collected data on 20 foreign medical school graduates in each of the 4 primary specialty types described above.So information on charges for 40 doctors (20 foreign and 20 USA medical school graduates)was obtained for each of the 4 specialties.The results for the ANOVA are summarized in the following table. -Referring to Table 11-8,is there evidence of a difference between the mean charges of foreign and USA medical school graduates?

TABLE 11-5 A hotel chain has identically small sized resorts in 5 locations in different small islands.The data that follow resulted from analyzing the hotel occupancies on randomly selected days in the 5 locations. Analysis of Variance * or p < 0.005,tabular value -True or False: Referring to Table 11-5,if a level of significance of 0.05 is chosen,the null hypothesis should be rejected.

TABLE 11-5 A hotel chain has identically small sized resorts in 5 locations in different small islands.The data that follow resulted from analyzing the hotel occupancies on randomly selected days in the 5 locations. Analysis of Variance * or p < 0.005,tabular value -True or False: Referring to Table 11-5,if a level of significance of 0.05 is chosen,the decision made indicates that all 5 locations have different mean occupancy rates.

TABLE 11-3 As part of an evaluation program,a sporting goods retailer wanted to compare the downhill coasting speeds of 4 brands of bicycles.She took 3 of each brand and determined their maximum downhill speeds.The results are presented in miles per hour in the table below. -Referring to Table 11-3,the null hypothesis for Levene's test for homogeneity of variances is

TABLE 11-3 As part of an evaluation program,a sporting goods retailer wanted to compare the downhill coasting speeds of 4 brands of bicycles.She took 3 of each brand and determined their maximum downhill speeds.The results are presented in miles per hour in the table below. -Referring to Table 11-3,what should be the conclusion for the Levene's test for homogeneity of variances at a 5% level of significance?

In a one-way ANOVA,

The F test statistic in a one-way ANOVA is

True or False: If you are comparing the mean sales among 3 different brands,you are dealing with a three-way ANOVA design.

A completely randomized design

TABLE 11-4 An agronomist wants to compare the crop yield of 3 varieties of chickpea seeds.She plants 15 fields,5 with each variety.She then measures the crop yield in bushels per acre.Treating this as a completely randomized design,the results are presented in the table that follows. -True or False: Referring to Table 11-4,the decision made at 0.005 level of significance implies that all 3 means are significantly different.