ABSTRACT
Y N xi Y X∼ + ∗( )β β σ0 1 2, | The expected value of the random variable Y is a straight-line function of X.
2. There is independence between the response variable values. 3. The independent or predictor variable is a quantitative variable, not necessar-
ily a random one. 4. The βi coefficients should not be affected by any power, other than the unit,
or by any trigonometric function. 5. The expected value of the residuals is zero, that is,
E e ii( ) = 0 for every value of “ ”
6. The variance of the residuals is constant and is equal to the variance of the response variable under the SLRM, that is,
var ei Y X( ) = σ /2
This variance is constant across the range of values of X (Homoscedasticity property).
