Question

Protein and Diastolic Blood Pressure A study was conducted with vegetarians to see whether the number of grams of protein each ate per day was related to diastolic blood pressure. The data are given here. If there is a significant relationship, predict the diastolic pressure of a vegetarian who consumes 8 grams of protein per day. (This information will be used for Exercises 10 and 12.)

Grams x 4 6.5 5 5.5 8 10 9 8.2 10.5

Pressure y 73 79 83 82 84 92 88 86 95

Answer 1

	X	Y	X * Y	X2	Y2
	4	73	292	16	5329
	6.5	79	513.5	42.25	6241
	5	83	415	25	6889
	5.5	82	451	30.25	6724
	8	84	672	64	7056
	10	92	920	100	8464
	9	88	792	81	7744
	8.2	86	705.2	67.24	7396
	10.5	95	997.5	110.25	9025
Total	66.7	762	5758.2	535.99	64868

r = 0.916

There is positive and strong relationship between variables.

Equation of regression line is Ŷ = a + bX

b = ( 9 * 5758.2 - 66.7 * 762 ) / ( 9 * 535.99 - ( 66.7 )²)
b = 2.662
a =( Σ Y - ( b * Σ X) ) / n
a =( 762 - ( 2.6623 * 66.7 ) ) / 9
a = 64.936
Equation of regression line becomes Ŷ = 64.936 + 2.662 X

When X = 8
Ŷ = 64.936 + 2.662 X
Ŷ = 64.936 + ( 2.662 * 8 )
Ŷ = 86.23