Exam 12: Analysis of Variance

Respond to the following questions using this partially completed one-way ANOVA table: Based on the analysis of variance F-test,what conclusion should be reached regarding the null hypothesis? Test using a significance level of 0.01.

Respond to the following questions using this partially completed one-way ANOVA table: Based on the analysis of variance F-test,what conclusion should be reached regarding the null hypothesis? Test using alpha = 0.05.

Suppose that you have just performed an experiment using the randomized complete block analysis of variance design and the output from Excel is shown as follows.The primary null hypothesis to be tested involves whether the means of the three groups are equal. ANOVA: Two-Factor Without Replication Using a significance level of 0.05,what conclusions should be made about the three groups? Which groups have different means? Discuss.

Explain what is meant by partitioning the sum of squares in a one-way analysis of variance application.

A manager is interested in testing whether three populations of interest have equal population means.Simple random samples of size 10 were selected from each population.The following ANOVA table and related statistics were computed: Conduct the appropriate test of the null hypothesis assuming that the populations have equal variances and the populations are normally distributed.Use a 0.05 level of significance.

In a two-factor ANOVA,the total sum of squares can be partitioned into four parts;the variation due to factor A,the variation due to factor B,the variation due to blocking,and the error variation.

Consider the following: How many populations are involved in this test?

A hotel chain has four hotels in Oregon.The general manager is interested in determining whether the mean length of stay is the same or different for the four hotels.She selects a random sample of n = 20 guests at each hotel and determines the number of nights they stayed.Assuming that she plans to test this using an alpha level equal to 0.05,which of the following is the correct critical value?

A large orchard owner in the state of Washington is interested in determining whether the mean number of bushels of peaches per acre is the same or different depending on the type of tree that is used.He also thinks that production may be affected by the type of fertilizer that is used.To test,he has set up a test in which a one-acre plot of peach trees with a combination each of 5 varieties and 3 fertilizer types are studied.The following data reflect the number of bushels of peaches on each acre plot. Assuming that the hypothesis tests will be conducted using an alpha equal 0.05 level,which of the following is true?

A car company is interested in testing to see whether the mean miles that a car engine will last without changing oil is the same or different depending on which brand of oil is used.The engineers also wish to control for the type of transmission (manual or automatic)that is used.To conduct this test,the car company obtains enough engines so that all four oil brands can be tested in a design that involves no replication.The following data reflect the miles the engine lasted until problems were encountered.Data are in thousands of miles. Assuming that the hypothesis tests are conducted using a significance level equal to 0.05,which of the following statements is true?

Analysis of variance can only be done for fixed effects.

Assume you are conducting a one-way analysis of variance using a 0.05 level of significance and have found that the p-value = 0.02.Which of the follow is correct regarding what you can conclude?

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 total number of degrees of freedom is 71.

In a one-way analysis of variance design,the total variation in the data across the various factor levels can be partitioned into two parts,the within sample variation and the between sample variation.

In a randomized complete block design analysis of variance,how many factors are there to be analyzed?

In a two-factor ANOVA,the minimum number of replications required in any cell is two,but all cells must have the same number of replications.

Respond to the following questions using this partially completed one-way ANOVA table: Fill in the ANOVA table with the missing values.

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 person's income tax returns are done by each of the three software packages and the time is recorded for each.Which of the following is true?

An advertising company is interested in determining if there is a difference in the mean sales that will be generated for a soft drink company based on which shelf the soft drinks are located.There are four possible shelf levels.The ad company wants to control for store size.The following data reflect the sales for one week at each combination of shelf level and store size. Based on the experimental design,the number of treatments is two.

Examine the following two-factor analysis of variance table: Does the ANOVA table indicate that the levels of factor B have equal means? Use a significance level of 0.05.