Exam 15: Analysis of Variance

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Four different brokerage houses were asked for stocks' earnings forecasts for the next year for five different corporations.The brokerage houses asked the analysts on staff who had experience with the corporations in question.Four analysts were surveyed at each brokerage house.Some descriptive statistics are listed below: -Is there sufficient evidence to reject the null hypothesis that there is no difference between the stocks' earning forecasts? Use α = 0.05.

An airline wants to select a computer software package for its reservation system.Four software packages (1,2,3,and 4)are commercially available.The airline will choose the package that bumps as few passengers,on the average,as possible during a month.An experiment is set up in which each package is used to make reservations for five randomly selected weeks.(A total of 20 weeks was included in the experiment. )The number of passengers bumped each week is given below. Package 1: 12,14,9,11,and 16 Package 2: 2,4,7,3,and 1 Package 3: 10,9,6,10,and 12 Package 4: 7,6,6,15,and 12 Which of the following tests is appropriate for testing the software's use?

The degrees of freedom for the F test in a one-way ANOVA,with n observations and k independent samples,are:

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider a two-way analysis of variance with one observation per cell and randomized blocks with the following results: -Compute the error mean squares.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: In a two-way ANOVA,there are 5 groups,3 blocks,and two observations per cell. -The number of degrees of freedom for the interaction term is:

Which of the following is the calculated p-value for Blocks? (Hint: Use Excel)

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider a two-way analysis of variance with one observation per cell and randomized blocks with the following results: -Compute the mean squares between blocks.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Random samples of two freshmen,two sophomores,two juniors,and two seniors each from four dormitories were asked to rate on a scale from 1 (poor)to 10 (excellent)the quality of the dormitory environment for studying.The results are shown in the table. -Test the null hypothesis that the population mean ratings are the same for the four student years.

The critical value of the Kruskal-Wallis test for comparing more than two independent samples is obtained from the chi-square distribution whenever each sample size is at least 5.

Is there sufficient evidence to reject the null hypothesis that there is no difference between the different manufacturers of light bulbs?

A randomized block design with four treatments and five blocks produced the following sum of squares values: SST = 1951,SSG = 349,SSB = 1414.Based on this data,the value of the SSE is calculated to be:

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A production manager monitors the output per hour of four workers over the course of four hours.The results are reproduced below. Assume that the populations from which the sample drawn are normally distributed. -Carry out the Kruskal-Wallis test for this data at α = 0.05 and write your conclusion.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A production manager monitors the output per hour of four workers over the course of four hours.The results are reproduced below. Assume that the populations from which the sample drawn are normally distributed. -Perform the appropriate analysis of variance and report the results.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A hotel chain has identically sized resorts in five locations.The data that follow resulted from analyzing the hotel occupancies on randomly selected days in the five locations. Analysis of Variance -What is the value that represents the within-group variation?

Which of the following expressions in a one-way ANOVA experiment,with n observations and k independent samples,is used to calculate the F test statistic?

Which of the following is the calculated p-value for Treatments? (Hint: Use Excel)

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: In conducting the Kruskal-Wallis test,independent random samples of sizes 5,7,8,and 7 were drawn from four populations and the sum of ranks in each of the samples were 84,100,96,and 98,respectively. -State the appropriate null and alternative hypotheses for this situation.

When there are two treatment groups,one-way ANOVA is equivalent to the pooled-variances t-test for difference between means.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A consumer group wanted to examine how long different life bulbs last.They selected three different light bulbs (60 watt,75 watt and 100 watt)from four different manufacturers.They generated the following statistics from the data. -What is the value of "A"?

In a one-way ANOVA with n observations and k independent samples,the within-groups sum of squares is: