An experiment was performed on a certain metal to determine
An experiment was performed on a certain metal to determine if the strength is a function of heating time (hours). Results based on 20 metal sheets are given below. Use the simple linear regression model.
 X = 40
 X2 = 200
 Y = 80
 Y2 = 1120
 XY = 460
 
 Find the estimated y intercept and slope and write the equation of the least squares regression line. Estimate Y when X is equal to 3 hours. Also determine the standard error, the Mean Square Error, the coefficient of determination and the coefficient of correlation.
Solution
a = (y)*(x^2) - (x)*( xy) / n(x^2)*(x^2) = - 1.....
 b= n(xy)-(x)( y) / n(x^2)- (x)^2 = 2.5......
 y = -1 +2.5*x....
 x=3...y = 6.5..
standard error(x) = 0.83667..
 men sq,. error of y= 72..
 coeff. of correlation = 0.96825..
 coeff. of determination = 0.9375...

