Question

The table shows the total 4-year cost (in thousands of dollars) and the Graduation rate (nearest percentage) from 4 randomly selected colleges/universities in the U.S.

Cost, x	250	138	81	85
Graduation Rate, y	83	92	57	32

The mean of x is 138.5 The standard deviation of x is 78.742

The mean of y is 66 The standard deviation of y is 27.092

The deviations and the z-scores for each x and y value are given below: Note: I tried my best with the tables below. BlackBoard has some issues with some of the font and symbols that were used.

(x - x̄ )	(y - ȳ )			Zx	Zy
111.5	17			1.416	0.627
-0.5	26			-0.006	0.960
-57.5	-9			-0.730	-0.332
-53.5	-34			-0.679	-1.255

a) Show the equations along with plugging the values into the corresponding equation on how the mean of the y values and the standard deviation of the y values were obtained. You may use a table above to help you with the standard deviation.

b) Find the correlation coefficient. You may use any of the tables above for help or any other equation method (Just stating the answer from a graphing calculator/technology will receive only 0 or 1 point for this question). Round the answer to 3 decimal places.

Answer 1