Win a copy of The Way of the Web Tester: A Beginner's Guide to Automating Tests this week in the Testing forum!

# program to calculate male to female ratio of a given number

nathan gibson
Ranch Hand
Posts: 120

i have the following code, and it works correctly, but im not sure how to make the results be partially biased towards the male side to represent the slightly greater number of males in the world. it is male: 50.34%, female: 49.66%. how can i incorporate this into the program? examples are welcome. thank you in advance.

Bear Bibeault
Author and ninkuma
Marshal
Posts: 65278
95
Before even thinking about writing a line of code, you should work out the math behind the problem. Give that a go.

Rob Spoor
Sheriff
Posts: 20709
68
nathan gibson wrote:boolean isMale = randomNumber > .5;

Just as a side note, you do know that the changes of being a female are larger than those of being a male this way, right?

randomNumber is between 0 (inclusive) and 1 (exclusive). For simplicity's sake let's only deal with steps of 0.01.
Someone is female for all values from 0 to 0.5 (inclusive) - that's 51 different values. Someone is male for all values from 0.51 to 0.99 (inclusive) - that's 49 different values. To have an even 50-50 match, turn the > into a >=.

Jesper de Jong
Java Cowboy
Saloon Keeper
Posts: 15574
46
nathan gibson wrote:it is male: 50.34%, female: 49.66%. how can i incorporate this into the program?

That would be very easy. You'd just have to change one thing in this line:

What do you think you'd have to change there to make the chance of isMale being true to .5034?

Campbell Ritchie
Sheriff
Posts: 50754
83
Surely that's < 0.5, Jesper???

salvin francis
Bartender
Posts: 1320
10
hi

Let me put this forward this way:

for simplicity, lets assume random gives you a value between 1 to 10 (both inclusive)
assuming that you want ratio of men >= 70% and female <=30%
wouldnt you say that if random <=7 its a Man else a Woman ?

now change the example to match 50.34% with random 0 to 1

nathan gibson
Ranch Hand
Posts: 120
oh. okay. i got ya, sorry, that was due to a bit of programmers block, thanks for the help. you guys are great.

Miklos Szeles
Ranch Hand
Posts: 142
Hi nathan,

I've noticed that this is the same program what you posted here. Only the variable names and interpretations are different. Can I ask you what's the purpose of this? I'm really curious.
According to the answers you got here you should also change the randomNumber > .5; to randomNumber >= .5; in the coin flipping program.

Jesper de Jong
Java Cowboy
Saloon Keeper
Posts: 15574
46
Campbell Ritchie wrote:Surely that's < 0.5, Jesper???

I just copied and pasted a line of code out of Nathan's original program.

Campbell Ritchie
Sheriff
Posts: 50754
83
Jesper Young wrote:I just copied and pasted a line . . .
Which will have well over 0.00000000000001% inaccuracy