1. For the same set of observations on a specified dependent variable two different independent variables were used to develop two separate simple linear regression models. A portion of the results is presented below. Based on the results given below, we can conclude:

Model 1 Model 2

R²= .85 R²= .92

std error = 1.91 std error = 1.65

There is no difference in the predictive ability between Model 1 and Model 2.

A prediction based on Model 1 is better than a prediction based on Model 2.

There is not sufficient information to determine which of the two models is superior for prediction purposes.

A prediction based on Model 2 is better than a prediction based on Model 1.

1. A history instructor has given the same pretest and the same final examination each semester. He is interested in determining if there is a relationship between the scores of the two tests. He computes the linear correlation coefficient, r,and notes that it is 1.15 (r = 1.15). What does this correlation coefficient value tell the instructor?

There is a strong positive correlation between the tests.

There is a strong negative correlation between the tests.

The correlation is something other than linear.

The history instructor has made a computational error.

1. Hugger polls contends that an agent conducts a mean of 53 in-depth home surveys every week.A streamlined survey form has been introduced in hopes of making it easier to conduct a survey.Hugger wants to evaluate its effectiveness.What type of test should Hugger use to determine if the number of interviews has increased?

one population test

two population z-test

two population t-test

simple regression