HELP A medical company tested a new drug on 100 people for possible side effects. This table shows the results.

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 .

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Write a function rule for the table