Exam 13: Correlation and Linear Regression

An assumption of linear regression states that for each value of X, there is a group of Y values that are statistically __________________ and normally distributed about the regression line.

Using the following information: If testing the hypothesis: H₀: ρ = 0, the computed t-statistic is __________.

A confidence interval can be determined for the mean value of Y for a given value of X.

Using the following information: Estimate the value of Ŷ when X = 4.

High school students were interested in a teacher's claim that the longer the length of time (hours) that a student studies for a test, the higher the test score. The students collected the data and the teacher did the regression analysis with the following results. To test the null hypothesis that the slope is zero, what are the t test statistic and the t-critical values using the 0.05 significance level?

Which value of r indicates a stronger correlation than 0.40?

A company wants to study the effect of an employee's length of employment on their number of workdays absent. The results of the regression analysis follow. What is the least squares equation?

A sales manager for an advertising agency believes there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis shows the following results: = 33.4. = 2814.4. The 95% prediction interval for a particular person making 30 calls is _______.

What does a coefficient of correlation of 0.70 infer?

Which of the following are true assumptions underlying linear regression? (1) For each value of X, there is a group of Y values that is normally distributed. (2) The means of these normal distributions of Y values all lie on the regression line. (3) The standard deviations of these normal distributions are equal.

The relationship between interest rates as a percent (X) and housing starts (Y) is given by the linear equation Ŷ = 4094 - 269X. For what interest rate will the maximum number of housing starts be achieved?

What is the alternate hypothesis to test the significance of the slope in a regression equation?

A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. What is the dependent variable?

What is the general form of the regression equation?

A company wants to study the effect of an employee's length of employment on their number of workdays absent. The results of the regression analysis follow. What is the slope of the linear equation?

_______________ is the technique used to predict or estimate the value of the dependent variable Y based on a selected value of an independent variable X.

A company wants to study the effect of an employee's length of employment on their number of workdays absent. The results of the regression analysis follow. What is the standard error of estimate?

Using the following information: The regression analysis can be summarized as follows:

A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. What is the independent variable?

A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression ANOVA shows the following results: What is the value of the coefficient of correlation?