Exam 15: Testing for Differences Between Groups and for Relationships Among Variables

A test of a hypothesis to determine if two groups differ with respect to the scores on one variable is called a(n)______.

Suppose that you used a 9-point rating scale and that you wanted to compare men who had an annual income over $50,000 (Group 1)with men who had an annual income less than or equal to $50,000 (Group 2)on their liking of a new product.If you studied 40 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?

A Z-test for differences of proportions requires a sample size greater than 100.

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

Which should be used when comparing the means of three groups to see if they are significantly different from one another?

A paired-sample t-test is an appropriate test for comparing the scores of two interval variables drawn from related populations.

A _____ is an investigation of a hypothesis stating that two (or more)groups differ with respect to measures on a variable.

The type of measurement,the nature of the comparison,and the number of groups to be compared influence the statistical choice.

If 25 of the 35 females in a research study agree with a statement,and 15 of the 35 males agree with this statement,the expected value for males-agree is _____.

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

The degrees of freedom are calculated as d.f. = n - 1 when using the t-test for comparing two means.

Which of the following is most appropriate if the purpose of the regression analysis is forecasting?

The Z-test for comparing two proportions is appropriate with which null hypothesis (H₀)?

In the regression equation,Y =α+ β X,Y is the _____.

Multicollinearity in regression analysis refers to the extent to which the independent variables are redundant.

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