If you mean 720/10^3, you do 10*10*10. This equals 1000. Now, do 720/1000. This is 0.72, or 72/100, which is your answer.
Answer:
h = yX -yr
Step-by-step explanation:
X=r-h/y
X - r = h/y
y*(X-r) = h
h = yX -yr
Fern's estimate is not correct because he rounded 548 wrong, it would be rounded to 550 instead since the number 8 is closer to 10. So the correct answer would be 420.