Given the total fixed-cost curve in gray and the total variable-cost curve in color, draw the total cost curve. Three points on the total variable-cost curve have been identified for reference. Use them to plot three points on the total cost curve with the point tool and then connect those points with the curved-line tool.

TFC : Horizontal Line parallel to X axis

TVC : Upward sloping inverse S shape curve from origin

TC : Upward sloping increase S shape curve, with Y axis intercept = TFC

Explanation:

Total Fixed cost [TFC] is the total production expenditure, done on fixed factors of production (Eg - on machine, building etc). It is incurred even at zero level of output, stays same (constant) irrespective of output level. So, it's curve is a  constant horizontal line.

Total Variable Cost [TVC] is the total production expenditure, done on variable factors of production (Eg - on raw material). It is zero at zero level of output,  directly related to level of output thereafter. It first increases at a decreasing rate, then increases at an increasing rate. So, it's curve is inverse S upward sloping curve from origin.

Total Cost [TC] is the total cost incurred on all factors of production (fixed & variable). It is sum of TVC & TFC. As TFC is constant at all levels of output, TC changes due to change in TVC. So, TC is also directly related to output level, first increases at increasing rate & then at decreasing rate. Hence, it is also a inverse S upward sloping curve. But, it also includes constant TFC. So, the curve has intercept on Y axis = TFC (it doesn't start from origin).