Exam 12: Analysis of Variance

A test is conducted to compare three different income tax software packages to determine whether there is any difference in the average time it takes to prepare income tax returns using the three different software packages.Ten different persons' income tax returns are done by each of the three software packages and the time is recorded for each.The computer results are shown below. ANOVA Assuming that the hypothesis tests are conducted using a significance level equal to 0.05,the Fisher's LSD value for multiple comparisons is:

Which of the following describes a treatment in a randomized complete block analysis of variance?

In conducting a one-way analysis of variance where the test statistic is less than the critical value,which of the following is correct?

The following sample data were recently collected in the course of conducting a randomized block analysis of variance.Based on these sample data,what conclusions should be reached about blocking effectiveness and about the means of the three populations involved? Test using a significance level equal to 0.05.

Six food critics each visited and rated four different restaurants.Each critic visited each restaurant on three separate occasions and recorded a score for each visit.The critical value for testing whether there is any difference among the four restaurants,using the 0.05 level of significance is approximately F = 2.8.

A randomized complete block analysis of variance allows the analyst to control for sources of variation that might adversely affect the analysis by using the concept of paired samples.

An Internet service provider is interested in testing to see if there is a difference in the mean weekly connect time for users who come into the service through a dial-up line,DSL,or cable Internet.To test this,the ISP has selected random samples from each category of user and recorded the connect time during a week period.The following data were collected: Which of the following would be the correct alternative hypotheses for the test to be conducted?

Consider the following: Test the main hypothesis of interest using α = 0.05

An Internet service provider is interested in testing to see if there is a difference in the mean weekly connect time for users who come into the service through a dial-up line,DSL,or cable Internet.To test this,the ISP has selected random samples from each category of user and recorded the connect time during a week period.The following data were collected: Assuming that the test is to be conducted at a 0.01 level of significance,what would the critical value be for this test?

The Tukey-Kramer method for multiple comparisons can only be used when the analysis of variance design is balanced.

In a randomized complete block design analysis of variance,which of the following correctly describes the number of degrees of freedom associated with the between sum of squares?

A national car rental agency is interested in determining whether the mean days that customers rent cars is the same between three of its major cities.The following data reflect the number of days people rented a car for a sample of people in each of three cities.Assuming that a one-way analysis of variance is to be performed,the total sum of squares is computed to be approximately 120.9.

Recently,a department store chain was interested in determining if there was a difference in the mean number of customers who enter the three stores in Seattle.The analysts set up a study in which the number of people entering the stores was counted depending on whether the day of the week was Saturday,Sunday,or a weekday.The following data were collected: Given this format and testing using an alpha level equal to 0.05,which of the following statements is true?

The one-way ANOVA test involves assuming that the population variances are equal.

In conducting one-way analysis of variance,the sample size for each group must be equal.

Examine the following two-factor analysis of variance table: Determine if the levels of factor A have equal means.Use a significance level of 0.05.

The Lottaburger restaurant chain in central New Mexico is conducting an analysis of its restaurants,which take pride in serving burgers and fries to go faster than the competition.As a part of its analysis,Lottaburger wants to determine if its speed of service is different across its four outlets.Orders at Lottaburger restaurants are tracked electronically,and the chain is able to determine the speed with which every order is filled.The chain decided to randomly sample 20 orders from each of the four restaurants it operates.The speed of service for each randomly sampled order was noted and is contained in the file Lottaburger. At the alpha = 0.05 level of service,can Lottaburger conclude that the speed of service is different across the four restaurants in the chain?

Frasier and Company manufactures four different products that it ships to customers throughout the United States.Delivery times are not a driving factor in the decision as to which type of carrier to use (rail,plane,or truck)to deliver the product.However,breakage cost is very expensive,and Frasier would like to select a mode of delivery that reduces the amount of product breakage.To help it reach a decision,the managers have decided to examine the dollar amount of breakage incurred by the three alternative modes of transportation under consideration.Because each product's fragility is different,the executives conducting the study wish to control for differences due to type of product.The company randomly assigns each product to each carrier and monitors the dollar breakage that occurs over the course of 100 shipments.The dollar breakage per shipment (to the nearest dollar)is as follows: Was Frasier and Company correct in its decision to block for type of product? Conduct the appropriate hypothesis test using a level of significance of 0.01.

A two-factor analysis of variance is conducted to test the effect the price and advertising have on sales of a particular brand of bottled water.Each week a combination of particular levels of price and advertising are used and the sales level is recorded.The computer results are shown below. ANOVA How many replications were used in this study?

Six food critics each visited and rated four different restaurants.Each critic visited each restaurant on three separate occasions and recorded a score for each visit.The number of degrees of freedom in the interaction row of the ANOVA table is 15.