The actual dimensions of a rectangle are 6 ft by 7 ft. Alex measures the sides to be 6.15 ft by 7.16 ft. In calculating the area, what is the relative error, to the nearest hundredth.

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 .

15 point ! ~ see if you know the answer to both you!

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?