Exam 13: Correlation and Linear Regression

One assumption underlying linear regression is that the X values are normally distributed.

In the regression equation, what does the letter "X" represent?

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. What is the coefficient of determination?

What is the variable used to predict another variable called?

Because the coefficient of determination is expressed as a percent, its value is between 0% and 100%.

The proportion of explained variation is called the _______________.

Perfect correlation means that the scatter diagram will appear as a _____________.

For an inverse relationship between two variables, the sign of the correlation coefficient is __________________.

What is the range of values for a coefficient of correlation?

If the correlation coefficient between two variables, X and Y, equals zero, what can be said of the variables X and Y?

If the coefficient of determination is 0.94, what can we say about the relationship between two variables?

The ___________ method determines the equation of a line that minimizes the sum of the squares of the vertical deviations about the line.

Using the following regression analysis: What is the coefficient of determination?

The population correlation coefficient is represented by ____.

The least squares technique minimizes the sum of the squares of the vertical distances between the actual Y values and the predicted values of Y.

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

An advertising company wanted to study the effect of advertising budget ($ millions) on the millions of ad impressions of consumers. The following regression analysis shows the results of the study. What is the decision regarding the null hypothesis that no relationship exists?

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 analysis shows the following results: What is the Y-intercept of the linear 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. Rounding to one decimal place, the 95% confidence interval for 30 calls is ___________.

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 standard error of estimate?