Thread: Help: why does it keep showing a wrong number?

I'm a beginner at C so I don't understand why my "False Positives" keep printing a large negative number?
Am I doing something wrong? Please help!

Code:

#include "stdio.h"

float falsePositive (float accuracy, float incidence, int population);




void question();


int main() 
{
    printf("QUESTION 1\n");    
    question();


    return 0;
}




void question() 
{
float accuracy, incidence;
int population;


    printf ("Enter population size:");
    scanf ("%d", &population);


    printf ("Enter the accuracy of the test as a percentages (e.g. 99):");
    scanf ("%f", &accuracy);


    printf ("Enter the incidence of the disease as a decimal fraction (e.g. .0001):");
    scanf ("%f", &incidence);


    printf("Population = %d, accuracy = %.2f, incidence = %.5f, False Positives = %.0f\n", population, accuracy, incidence, falsePositive(accuracy, incidence, population));
}




float falsePositive (float accuracy, float incidence, int population)
{
    float falsepositives, healthypeople;
    healthypeople = (population * (1-incidence)); 
    falsepositives = (healthypeople * (1-accuracy));


    return falsepositives;
}