a) The y-intercept is (0,38,000).
b) The y-intercept of 38,000 means that Adam's base salary is $38,000.
c) The slope is 0.28.
d) The slope of 0.28 means that for every $1 increase in total sales, Adam's salary increases by $0.28.
e) If Adam made $45,000 total annual salary, his total sales would be $196,429. This can be calculated by setting y = 45,000 and solving for x in the equation y = 0.28x + 38,000.