Assuming I have a linear regression model of the form:
Y = a + (b1*fact1) + (b2*fact2) + b3*(fact1*fact2) + b4*other_var
where, fact1, fact2 are categorical variables of 2 factors each, YES and NO and other_var is a continuous variable and in the regression model, b3 represents the coefficient when both fact1=fact2=YES
a) is the intercept a, the effect on response Y in the case where both fact1 and fact2 are 0?
b) is the effect on the response Y when fact1=fact2=YES, given by b1+b2+b3?
c) is the effect on the response Y when fact1=YES, fact2=NO, given just by b1?