Stats M. 11

Question 1

slope of an estimated regression equation

Answer 1

y = Bo + B1 (x)

Question 2

RSquare tells us what

Answer 2

the percentage of variation in the response variable that can be explained by the linear relationship between the response variable and the predictor variable

Question 3

if B1 > 0

Answer 3

the graph of the regression equation slopes up

Question 4

if B1<0

Answer 4

the graph of the regression equation slopes down

Question 5

if B1=0

Answer 5

the graph of the regression equation is horizontal

Question 6

L
I
N
E

Answer 6

Linearity
Independence
normality
equal variance

Question 7

linearity=

Answer 7

there is a linear relationship between explanatory variable and the response variable
scatterplot: look for linear relationship
residuals vs fitted plot: look for no clear pattern

Question 8

independence=

Answer 8

the observations of the response variable are independent of each other
-check whether good sampling techniques were used

Question 9

normality=

Answer 9

at each setting of the predictor variable, the distribution of the response variable is normal
-QQ plot: check to see whether the points on the plot follow the diagonal line on the plot

Question 10

equal variance=

Answer 10

at each setting of the predictor variable the distribution of the response variable has the same standard deviation
-residuals vs fitted plot: we want to see a horizontal band of points that is centered and symmetric about the x-axis

Question 11

Ho:
Ha:

Answer 11

Ho: the predictor variable is NOT useful for predicting the response variable B1 = 0
Ha: the predictor variable is useful for predicting the response variable B1 =/ 0