Lance is selling T-shirts for $10 each and hats for $12.50 each. He wants to earn at least $400 per week to cover his expenses. Which graph best represents the number of T-shirts and hats Lance should sell to meet his goal?

Step-by-step explanation:

1 number

if we use a graphing calculator, there is only one such number that satisfies the conclusion of the mean value theorem, that is, a number such that

where the right-hand side is the average rate of change of f on the interval [0.5,0.75], which is the slope of the secant line.

in the attached graph, the black line is the secant line which has its slope as the average rate of change of f on [0.5,0.75], while the orange line is the only tangent line to the graph of f in the interval that satisfies the mvt conclusion.