Stats Final

In a simple linear regression problem, r and b1

must have the same sign

The least squares method minimizes one of the following?

SSE

What do we mean when we say that a simple linear regression model is "statistically" useful?

The model is a better predictor of Y than the sample mean, Y bar

If the correlation coefficient (r)=100, then

all the data points must fall exactly on a straight line with a positive slope

A measure of the degree of relatedness of two variables is

correlation

The difference between the actual y value and the predicted y value found using a regression equation is called the

residual

Testing for the existence of correlation is equivalent to

testing for the existence of the slope (B1)

Residuals represent

the difference between the actual y values and the predicted y values

An assumption of simple regression is

the error terms are independent

If a categorical independent variable contains 4 categories (levels), the number of dummy variable(s) needed to uniquely represent these categories is

3

The coefficient of determination must be

between 0 and +1

If the error variances in regression are not constant, the data are

heteroscedastic

What do you mean when we say that a simple linear regression model is "statistically" useful?

the model is a better predictor of Y than the sample Y bar

A dummy variable is used as an independent variable in a regression model when

the variable involved is categorical