Exam 15: Testing for Differences Between Groups and for Predictive Relationships

In multiple regression,dummy variables are those that have no effect on the dependent variable.

What is ANOVA and when is it the appropriate statistical technique? What test is used to determine significance?

____________________ may be used to assess problems with multicollinearity.

In the regression equation,Y = a + YX,a is the symbol for the ____.

To use the chi-square test,both variables in a 2 x 2 contingency table must be measured on a ratio scale.

Which analysis is portrayed by the equation: Y = b₀ + β₁X₁ + β₂X₂ + β₃X₃...+ βnXn?

The ____________________ is the mean of a variable over all observations.

In using the Z-test for comparing two proportions,the null hypothesis is typically stated as ____.

If the purpose of the regression analysis is forecasting,then standardized regression estimates are most appropriate.

When the difference between two groups is measured,bivariate statistics are used.

The null hypothesis for an ANOVA test comparing the means of three groups is: µ₁ ₌ µ₂ ₌ µ₃.

The degrees of freedom are calculated as df = n _ 1 when using the t-test for comparing two means,where n = n₁ + n₂.

Suppose that you are using a 9-point rating scale to compare men who have an annual income over $50,000 (Group 1)with men who have an annual income less than or equal to $50,000 (Group 2)with regard to their assessment of a new product.There are forty men in Group 1 and they have a mean of 7 and a standard deviation of 2.5,while the 35 men in Group 2 have a mean of 5 and a standard deviation of 1.4.What is the approximate value of t using the t-test?

Multivariate dependence techniques are variants of the ____,which is a way of modeling some process based on how different variables cause fluctuations from the average dependent variable.

A variable that has two distinct levels that are coded as either zero or one is called a(n)____.

The chi-square test requires that the expected frequency in each cell of the contingency table be at least 30.

The statistical test used to determine whether there is more variability in the scores of one sample than in the scores of another sample is the ____________________.

Which type of analysis involves three or more variables?

Multivariate statistical analysis permits the researcher to consider more than one dependent variable at the same time.

Discuss when a paired-samples t-test is appropriate and give an example of when it should be used.