What percent of 162 is 72.9

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

What is the length of the midsegment of a trapezoid with bases of length 15 and 25 ?