Econometrics help urgently

1. Imagine that you encounter a model looking like the following image (15 points) SALARY if x =1 slope is b, + b, If x,=0 slope is b, b. + b, Do TOTAL YEARS OF EXPERIENCE y = b + b,x, + b,x, + b,xx, a) Given that this is a relationship between experience and salary, what do you think the variable x2 is, assuming that x1 is the total years of experience? Give any reasonable guess and explain why it would make sense that x2 is actually what you guess it is? b) Given your guess in part a) of the exercise, please tell me how to interpret the estimated coefficients exactly. c) Write up the same model in semilogarithmic form and detail how exactly the interpretation of the coefficients by and b; would change (because the interpretation of b, would simply be that a one unit change in experience causes a bj percentage change in salary. That's clear. But what about the rest of the coefficients?)