Exam 13: Implementing Basic Differences Tests

Let's say we wanted to see if there was a significant difference between your class's mean GPA when you were all freshmen and your class's mean GPA today.What is the proper SPSS command that you would use to test this difference?

A winery sees the market in three distinct segments based upon usage of wine;a dog food manufacturer sees the dog food market in 12 segments;Toyota offers 17 different models ranging from a two-seater sports car to the Avalon luxury car.These are all examples illustrating how:

To test whether a true difference exists between two group percentages,we test the ________ hypothesis.

SPSS will report analysis of differences tests in terms of t tests.

Although there are separate differences tests for means versus percentages,all these test for differences between two or more values.As long as you have at least two percentages or two means,any one test will be appropriate.

Which of the following commands would we use in SPSS to test for a difference between two means - one generated from a sample of heavy users of our brand and the other generated from a sample of nonusers of our brand?

Tommy Prothro,a marketing manager for Golden Snack Bars,has commissioned marketing research to determine if one recipe of snack bar is superior to another recipe.More than 400 persons who were "snack bar eaters" were involved in taste tests and,after tasting both recipes,they were asked which recipe they would purchase the next time they purchased snack bars.Tommy is now looking at the data and he sees that recipe A had 53 percent stating a preference,whereas recipe B had 47 percent.Tommy's brand manager felt this was "significant" evidence that the firm should produce recipe A.But Tommy wanted more evidence so he asked the research firm to run a test to determine if there was a significant difference between the two recipes.By doing this,Tommy would get information that would allow him to determine:

To be useful to the marketing researcher or manager,differences must be:

Let's assume there are juniors,seniors,and graduate students in your class and we want to know if their average GPAs differ.What is the proper statistical test?

ANOVA is called a "signal flag" procedure,meaning that if it shows significance:

The assumption of equal variances between two samples for differences testing,is evaluated by:

In interpreting the output for the Duncan's multiple range test,different means are listed as different subsets.

The t value is used for many tests instead of the z value because:

In the test to determine significance difference between two means generated by independent samples,there is no provision for testing a directional hypothesis such as "males drink more soft drinks per week than females."

P values can take on a range of:

Iams marketing over 20 different types of dog food,Toyota marketing over 20 different types of cars,and Boeing having five different types of commercial jets and a separate business jets division are all examples of:

Which of the following is NOT part of the advantages that ANOVA has over performing multiple t tests of the significance of the differences between means?

Suppose Hershey's chocolate managers wanted to test for differences between usage of coupons among different combinations of two or more grouping variables,such as age groups and occupation groups.The appropriate procedure to test for differences among the means of these groups would be:

Which best represents the correct meaning of statistical significance of differences?

When a computed z value (for a test for differences between two percentages),4.21,is larger than the standard z value,1.96,then this amounts to: