1.In a study concerned with the relationship between two variables, X and Y, the following data were obtained:

Mean of X = 119

Mean of Y = 1.30

S.D. of X = 10

S.D. of Y = 0.55

r = 0.7

a)Sally obtained a score of 130 on the X-variable.Predict her score on the Yvariable.

b)A score of 1.28 on the Y-variable was predicted for Bill.What was his score on the X-variable?

c)Determine the standard error of estimate for Y.

2.The variance of Y is 400 and the correlation between X and Y is 0.50.

a)What is the variance error of estimate in predicting Y from X?

b)What is the variance of the predicted values?

3.A student obtains a score on Test X that is 1.5 standard deviations above the mean.What standard score would you predict for him on test Y if r equals: (a)0.0(b)0.40(c)0.80(d)1.0(e)-0.50(f)-0.80

4.Shown below are the scores of 20 female college professors on a measure of satisfaction with their work (Y), and a measure of satisfaction with their lives in general (X).Also shown are the means, standard deviations, and r_xy.

Prof.12345678910 11121314151617181920

X:5764605949576253665561486958615568566255

Y:4453475036495440524849396046484357475145

Mean of X = 58.75S.D. of X = 5.64Mean of Y = 47.9S.D of Y = 5.9r_xy = 0.94

(a)Find the regression equation for predicting work satisfaction (Y) from life satisfaction (X).

(b)Predict work satisfaction (Y) scores from X scores of 50, and 70.

(c)Graph the 20 pairs of X and Y scores in a scatter plot.On the same graph, plot the regression line obtained in (a) above.(Note: This can be done by first plotting the point representing X = 50 and the predicted Y score that you calculated in (b) above, and then do the same thing for the X score of 70.Then connect these two points on the graph with a straight line, and presto!You have your regression line.In other words, the regression line is the line that runs through all ofthe predicted Y-scores if you were to plot them on the graph.)

(d)Compute the Standard Error of Estimate (S_e).What does this statistic represent?Relate it to what you have plotted on the graph.

5.A study was undertaken to find the relationship between "emotional stability" and performance in college.The following results were obtained"

Mean of X = 49 Mean of Y = 1.35

S_x=12S_y=0.5

r = 0.36

(a)Norm obtained a score of 85 on the X-variable.What is your prediction of his score on the Y-variable?

(b)Determine the standard error of estimate of X and Y.

(c)What proportion of the total variation in Y is accounted for by X?