Given the following points: (-2, 0), (-1,0), (0,1), (1, 1) and (2, 3) What is the Y intercept of the regression line?
- 1.0
- None of these answers
- 1.5
- 0.7
- 0.0
Answer(s): A
Explanation:
For this, you need to create tables with columns for X,Y,XY,X^2,Y' and Y-Y'. This will be as follows.
XYXY X^2 Y'Y-Y'
-2004-0.40.4
-10010.3-0.3
010010
11111.7-0.7
23642.40.6
Sum057100
N=5.
The regression equation is Y' = a + bX.
First, find the slope, which is b, use the formula
b = [n(SXY)-(SX)(SY)]/[n(SX^2)-(SX)^2] where S stands for "Sum of." b = [5(0)-(0)(5)]/[5(10)-0]=0.7 The Y intercept is a.
a = [S(Y)/n]-b[SX/n]
a = 5/5 - 0.7[0/5] = 1.