<span>valid. She used a representative sample
</span>because she correctly found the average and 18,000 is a reasonable number to get for a the problem
1. All you have to do to find the area of the figure. IS first find the area of the rectangle. This is easy because all you have to do is base times height.
22 x 17 = 374
Now to find the area of the triangle all you have to do is do base times height like a rectangle, but then divide it by 2 afterwords.
19 x 12 = 228 ÷ 2 = 114.
Now add the two area's together:
374 + 114 = 488.
Just do the same with the one below, I've altered the pic a bit to make it easier.
First you have to get the number on the right 40 to equal 100 so do 40x2=80- +40x1.5= 100
Then do the same thing to the first number 8 so 8x2=16+8x1.5=20
then you have 20/100 right so then that number over 100 is the percent that you get ^-^ 20%