Math Help - percentage problem

1. percentage problem

Hi

This is just a one off problem.
Two numbers 9 and 27 average to give 9.5
What % of 9 and what % of 27 gives 9.5 at all please

Can anyone be kind enough to help please with some workings
Thanks
Mark

2. Re: percentage problem

To find out how many % is 9 of 9.5, you can write it as an equation
$9.5\cdot x=9\\\\x=\frac{9.5}{9}$

9.5 is therefore 105.5% of 9.

3. Re: percentage problem

Thanks, i dont see how you got 94.7 ?

9.5/9= 1.05???
Im sorry but im not great at maths

4. Re: percentage problem

if 9 is 94.7% of 9.5 thien it is 8.99, this means that 27 is 5.3% and is 1.4 which gives a value of 10.4 and not 9.5??
I just dont get this

5. Re: percentage problem

You are basically finding a weighted average of 9 and 27. Let x be a percentage. 9x + (1-x)27 = 9.5

-18x + 27 = 9.5

-18x = -17.5

x = 17.5/18 which is approximately 97.2%. So approximately 97.2% of 9 and approximately 2.8% of 27

Howard Heller
InteractiveMathTutor.com

6. Re: percentage problem

Originally Posted by mscates176
Thanks, i dont see how you got 94.7 ?

9.5/9= 1.05???
Im sorry but im not great at maths
Whoops, I corrected my problem. I confused myself there.

An easier approach will be to use my preferred method of asking: ''How many % is 9 of 9.5?''. When you ask this, you can put the first number in the denominator (up) and the second number in the numerator (down) and write $\frac {9}{9.5}=0.94.7$ or 94.7%. Percent just means 'per cent' which just means one out of a hundred. 1% is literally the number 0.01.

This works for any pair of numbers. ''How many percent is 27 of 2 9.5?'' $\frac{27}{9.5}=2.84$ or 284%.

7. Re: percentage problem

Thanks, but this still doesn't work because it means that the 27 is 5.3% which then gives a total value of 10.4

8. Re: percentage problem

Originally Posted by mscates176
Thanks, but this still doesn't work because it means that the 27 is 5.3% which then gives a total value of 10.4
Yes, I notice now that you are talking about weighted averages. That is another form of problem all together. IMTinstructor answered with respect to that up there.

9. Re: percentage problem

Thankyou for your help the 97.2 is correct. That works.