# How to find the proportion of people who play an instrument

1. Nov 10, 2013

### BCCB

I have data outlining the number of people who play a musical instrument

and data outlining the total number of people in each city

play an instrument.............population
255................................1 009 924
179................................3 500 048
556................................ 957 293
etc.

how do I write the proportion of people who play an instrument per 100 000 people?

Should I do it like this?

play an instrument.............population
255................................1 009 924/100 000= 10.09924
179................................3 500 048/100 000=35.00048
556................................ 957 293/100 000=9.57293

255/10.09924=25.25
179/35.00048= 5.11422
556/9.57293=58.01

Thanks :)

2. Nov 10, 2013

### Simon Bridge

It's like finding percentages ... only, in this case, you are finding the percentum-milli (?)

If n people out of N play an instrument then 100(n/N)% play an instrument, which is 100000(n/N) out of 100000.

eg. If there are 50,000 people in the city and 2 of them play an instrument, then 4 out of 100000 play an instrument.

It does not matter which order you do the division and multiplications - so what you did works too.
You did n/(N/100000) = 100000(n/N) - same thing see?

But this way helps you keep it straight in your head what you are doing.

3. Nov 11, 2013

### goldust

Depending on the country, I suppose. In Africa, maybe as high as 10%.

4. Nov 12, 2013