Simple Linear Regression Flashcards
A numerical measure of linear association between two variables is the
covariance
A numerical measure of linear association between two variables is the
correlation coefficient
The coefficient of correlation
cannot be larger than 1
In a regression analysis, the error term is a random variable with a mean or expected value of
zero
The mathematical equation relating the independent variable to the expected value of the dependent variable; that is, E(y) = 0 + 1x, is known as
regression equation
A regression analysis between sales (Y in $1000) and advertising (X in dollars) resulted in the following equation
Y hat= 30,000 + 4 X
increase of $1 in advertising is associated with an increase of $4,000 in sales
In a simple regression analysis (where Y is a dependent and X an independent variable), if the Y intercept is positive, then
None of these alternatives is correct.
The equation that describes how the dependent variable (y) is related to the independent variable (x) is called
the regression model
In a regression analysis, the variable that is being predicted
is the dependent variable
A regression analysis between sales (in $1000) and price (in dollars) resulted in the following equation
Y hat = 60 - 8X
The above equation implies that an
increase of $1 in price is associated with a decrease of $8000 in sales
A regression analysis between demand (Y in 1000 units) and price (X in dollars) resulted in the following equation
Y8 = 9 - 3X
The above equation implies that if the price is increased by $1, the demand is expected to
decrease by 3,000 units
A least squares regression line
may be used to predict a value of y if the corresponding x value is given
The coefficient of determination
cannot be negative
The value of the coefficient of correlation (R)
can be equal to the value of the coefficient of determination (R2)
In a regression analysis, the coefficient of determination is 0.4225. The coefficient of correlation in this situation is
0.65