Question

Use pair data values and the summations given to
x:& 1 & & & & 3 & 5 & & 7 & & 9
y:& 10& & & 8& & 7& & & 4& & & 2

Σx= 25;& & & Σy= 31;& & & & & Σxy= 115:& & & & Σx² = 165

a. Find the equation for the least squares regression line.
b. Predict the value of y when x is 6 using your equation

Answer 1

1. The average x and y are
x = 25/5 = 5
y = 31/5 = 6.2
2. The regression coefficient is


thus the equation of the least squares would be


When x= 6,
y = -6 + 11.2 = 5.2