80 inches, diameter is twice radius
No it is not proportional. Since she brought the last apple for 1/2 the price, the equation won’t be linear (straight line) anymore so it won’t be proportional. Proportional means the same unit rate.
3/4+2/6+1/2 = 9/12+4/12+6/12 = 19/12 Brendan has 1 7/12 leftover pizzas. THis is achieved by multiplying for a common denominator and adding
19/12-2/3 = 19/12-8/12 = 11/12 Brendan has 11/12 more pizzas than Steve.