Answer: James had $350 in his cash register and earned $50 each day in sales.
Explanation:
Given Table:-
Day Dollars
0 350
2 450
4 550
6 650
We know that the rate of change in function f(x)=

Thus rate of change in sales from day 0 to day 6=

Thus, James had $350 (as this is the initial value at day 0) in his cash register and earned $50 each day in sales.