Question

Can u guys check my answer?
What is the approximate volume of a sphere with a radius of 12 ft?
Use 3.14 to approximate pi and express your answer in hundredths.
77234.55998 ft?

Answer 1

@MrNood

Answer 2

what formula did you use ?

Answer 3

4/3*3.14*r^3

Answer 4

and r is 12
so figure out
4*3.14*12*12*12/3

Answer 5

I already did this.

Answer 6

do it again

Answer 7

the formula is 4/3*3.14*r^3

Answer 8

yes.

Answer 9

i got 7264.56001

Answer 10

you have the correct formula, but you did something wrong when doing the arithmetic
if you use 3.14 for pi, you will only get 2 decimals in that answer.

Answer 11

what did i do wrong?

Answer 12

notice that
4*3.14*12*12*12/3

the last 12/3 is 4, so the problem is
4*3.14*12*12*4

which you can write as
4*4 * 12*12 * 3.14
or
16* 144 * 3.14

Answer 13

First get the correct answer. then we can figure out what you did wrong.

Answer 14

7234.56

Answer 15

yes. that looks good.

now try
4*3.14*12*12*12/3
on you calculator. you should get 7234.56

Answer 16

but y do u have to divide by 3?

Answer 17

and i did get 7234.56

Answer 18

I wrote 4/3 * 12*12*12*3.14 as 4*12*12*12*3.14/3
if you write it as a fraction:
\[ \frac{4}{3} \cdot \frac{3.14 \cdot 12^3 }{1} \]
and multiply top times top and bottom times bottom:
\[ \frac{3.14 \cdot 12^3 }{3} \]
and that means you can first figure out the top, and then divide by 3

Answer 19

If you play with numbers, you learn these ideas

Answer 20

ok thx

Answer 21

* I forgot the 4 up top
\[ \frac{4 \cdot 3.14 \cdot 12^3 }{3}\]

Answer 22

Can you figure out what you did to get 77234.55998 ?

Answer 23

because you don't want to do that

Answer 24

ohh ok i get i know thx a lot.