Question

Please see image below I think the answer is the first one

Answer 1

The slope of a function

f(x) = mx + b

is m, i.e., the constant multiplying the variable x.

Thus, for the given function

S = 400 + 0.15c

c is the variable (sales). So, the slope is 0.15.

Also, for each dollar in sales, the initial value of 400 increases by 0.15 * 1 = 0.15 dollars.

Therefore, the correct answer is the first option.