Math Is Fun Forum

bobw

Guest

what % is 38 of 216

I need to understand how you find what percentage a particular number is of another number. Thanks

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: what % is 38 of 216

Hi bobw;

Great username!

Put 38 over 216 like this 38 / 216. Now reduce as far as you can to 19 / 109. Not really necessary just makes the following division a little easier.

Divide 19 by 109 using long division to get a decimal. You should get .174311...

Now multiply that by 100 to get a percentage:

100 * .174311 = 17.43 %

So 38 is approximately 17.43 % of 216.

Last edited by bobbym (2009-10-25 08:42:25)

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

goteamusa

Member

Registered: 2009-10-28

Posts: 7

Re: what % is 38 of 216

An alternative method would be to use proportions (it is the same thing as post #2 just in a different form).

38, "a" is what percent of 216, "b"? :

First write your two numbers as a fraction: 38/216.
Now, a percent is what fraction of 100 a number is, so you can write what percent 38 is of 216 as a fraction: x (whatever percent of 216 38 is)/100
So now you have: x/100.
So 38 is the same ratio to 216 as x is to 100 so you can set the two expressions equal: 38/216 = x/100.
Now you solve the equation:
                                         38/216 = x/100
                                         100(38/216)=100(x/100)
                                         3800/216=(100/100)x
                                         17.5925... = (1)x
                                          17.5925....=x
So, 38 is approximately 17.5926% of 216.

If you wish, you can check your answer.
Take your percent (17.5926) and divide it by 100: 17.5926/100 = .175926
Now multiply this number by the denominator of your other fraction (that is "b" in the expression "find the percent a of b"), so in this instance we would have (.175926)(216).
If you set your proportion up correctly, this should equal "a" :
(.175926)(216)= 38.000016.
This is 0.000016 different than what you should get. This error is due to rounding, if you carried the decimals in 17.5925... to infinity, then you would get exactly 38.
Since 38 = a, the solution "checks".

More generally, if you wish to know what percent, "x", "a" is of "b", then just set up and solve the proportion : a/b = x/100.
x will be your answer.

Last edited by goteamusa (2009-10-28 16:27:57)

---

Let us then be up and doing, with a heart for any fate, still achieving still pursuing, learn to labor and to wait.
~Longfellow from "A Psalm of Life"

Sarah12

Guest

Re: what % is 38 of 216

You can get A tutor to help you with it.

dhuill

Member

Registered: 2009-10-30

Posts: 6

Re: what % is 38 of 216

Or you can use an online tutor like www.secondteacher.com, only $25 a year!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: what % is 38 of 216

Hi Guys;

I think bobw (great username) got all the tutoring he's ever gonna need on that problem.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.