I am so flaming useless at maths!!

top_drawer_2

hi,

I am trying to work out how much X% is of some huge numbers and I just cant come up with anything sensible. The numbers relate to how many people suffered with an illness last year....

ie 16% got xyz disease. The total number of people checked for this disease was 3,170,640.

the answers i've got by calculating the how much 1% is 0.000031539 thus 16% is 0.0000504629 (!!!) this doesnt tell me how many people actually suffered!!

Can anyone help?

Thanks

Jen

Sparkkee

How did you get those figures?

1% of the people checked = number of people checked divided by 100 = 31,706.4

16% = 16 x 1% = 16 x 31,706.4 = 507,302.4

so, 507,302 people got the disease.

Rikki

For 1% of the people checked, you need to divided by 100 is 31,706.4

Now 16 x 1% is 507,302.4

Answer is 507,302.4 people.

Mind you its been a few years since I did maths at school.

Oldernotwiser

top_drawer wrote: »

hi,

I am trying to work out how much X% is of some huge numbers and I just cant come up with anything sensible. The numbers relate to how many people suffered with an illness last year....

ie 16% got xyz disease. The total number of people checked for this disease was 3,170,640.

the answers i've got by calculating the how much 1% is 0.000031539 thus 16% is 0.0000504629 (!!!) this doesnt tell me how many people actually suffered!!

Can anyone help?

Thanks

Jen

This is what happens when you use calculators incorrectly. Do it on paper, it's much easier!

Lokolo

Oldernotwiser wrote: »

This is what happens when you use calculators incorrectly. Do it on paper, it's much easier!

I don't know about you but trying to find the radian value using Tan-1(3/4) would be pretty hard on paper.....

top_drawer_2

lol I'm supposed to be designing a intervention aimed at reassuring people they are unlikely to actually get this disease .....

those figures dont sound very reassuring!

Jen

whitfreak

But if you sketch the graph you can estimate it.... about pi/5 right?

top_drawer_2

whitfreak wrote: »

But if you sketch the graph you can estimate it.... about pi/5 right?

pi/5 ??

sorry but it needs to be exceedingly simple for me .....

whitfreak

Side note, I now realise why so many grad jobs have maths tests as part of the recuirtment. I'm just lucky there isnt a spelling test...

Back on topic. There are statistical tests which can be done to give a confience interval on whether the sampled population is representative of the actually population. Although you've got a large sample size so that isnt really a big issue.

top_drawer_2

mahhh right yes ....

my spelling isnt too bad ... I just cant folow maths though.



I dont actually have the data or anything - the figures are from a NHS website but I need to design this intervention around them.

Jen

whitfreak

sorry top drawer, pi/5 was in answer to Lokolo Tan-1 comment. I should have quoted.
The others have answered your question. When dealing with percentages it can be easier to do things by hand with fractions (16%=16/100). It in theory stops you from dividing when you should be multiplying etc. Which looks like what you did, as 1/your 1% answer gives the correct 1% answer (give or take a 0.4)...

Good luck