Question

C language
you are to write a a program that will first read in
the heights and weights of a series of people from a file named 
values.dat.  Create this file using your editor so that each line
contains a height and corresponding weight.  For instance, it might look likea:

69.0  125.0
44.0  100.0
60.0  155.0
49.0  190.0
65.0  115.0
50.0  80.0
30.0  129.0
72.0  99.0
68.0  122.0
50.0  105.0
and so on.

The formula for the standard deviation of a series of numbers x[0], x[1] ... x[n] is

std = sqrt( sum( (x[i] - xbar)**2 ) / (n) )

where xbar is the average value of x, n is the number of people,
and **2 means squared.

------header file------

#define MAXNUM 100

typedef struct person

{

double height;

double weight;

} Person;

//prototypes follow:

int getData(FILE *input, Person people[]);

void getAverages(Person people[], double *aveHeight, double *aveWeight, int

numPeople);

void getStandardDevs(Person people[], double aveHeight, double aveWeight,

double *stdHeight, double *stdWeight, int numPeople);

--------main template ----------

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#define MAXNUM 100

#include "stats.h"

void main( void )

{

FILE *input;

Person people[MAXNUM];

int numPeople = 0;

double aveHeight = 0.0, aveWeight = 0.0, stdHeight = 0.0, stdWeight = 0.0;

numPeople = getData(input, people);

getAverages(people, &aveHeight, &aveWeight, numPeople);

getStandardDevs(people, aveHeight, aveWeight, &stdHeight, &stdWeight, numPeople);

printf("\n\n\n\n\n\nThe average height is %lf\n", aveHeight);

printf("The average weight is %lf\n", aveWeight);

printf("The standard deviation of the heights is %lf\n", stdHeight);

printf("The standard deviation of the weights is %lf\n\n\n\n\n\n", stdWeight);

}

int getData( FILE* input, Person people[])

{

int numPeople = 0;

input = fopen( "values.dat", "r" ); // How to read file

if ( input == NULL )

{

printf( "\"values.dat\" does not exist!!\n" );

}

/*

your code here

*/

fclose(input);

return numPeople;

} // getData()

void getAverages( Person people[], double* aveHeight, double* aveWeight, int

numPeople)

{

/*

your code here

*/

} // getAverages()

void getStandardDevs( Person people[], double aveHeight, double aveWeight, double*

stdHeight, double* stdWeight, int numPeople )

{

/*

your code here

*/

} // getStandardDevs()

Answer 1

------header file------

#define MAXNUM 100

typedef struct person

{

double height;

double weight;

} Person;

//prototypes follow:

int getData(FILE *input, Person people[]);

void getAverages(Person people[], double *aveHeight, double *aveWeight, int

numPeople);

void getStandardDevs(Person people[], double aveHeight, double aveWeight,

double *stdHeight, double *stdWeight, int numPeople);

--------main template ----------

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define MAXNUM 100
#include "stats.h"
void main(void)
{
   FILE* input=NULL;
   Person people[MAXNUM];
   int numPeople = 0;
   double aveHeight = 0.0, aveWeight = 0.0, stdHeight = 0.0, stdWeight = 0.0;
   numPeople = getData(input, people);
   getAverages(people, &aveHeight, &aveWeight, numPeople);
   getStandardDevs(people, aveHeight, aveWeight, &stdHeight, &stdWeight, numPeople);
   printf("\n\n\n\n\n\nThe average height is %lf\n", aveHeight);
   printf("The average weight is %lf\n", aveWeight);
   printf("The standard deviation of the heights is %lf\n", stdHeight);
   printf("The standard deviation of the weights is %lf\n\n\n\n\n\n", stdWeight);
}
int getData(FILE* input, Person people[])
{
   int numPeople = 0;
   #pragma warning(disable : 4996)
   input = fopen("values.dat", "r"); // How to read file
   if (input == NULL)
   {
       printf("\"values.dat\" does not exist!!\n");
   }
   double h, w;
while (fscanf(input, "%lf %lf", &h, &w) != EOF) {
       Person p = { h,w };
       people[numPeople++] = p;
   }
   ;
   fclose(input);
   return numPeople;
} // getData()
void getAverages(Person people[], double* aveHeight, double* aveWeight, int
   numPeople)
{
   double sumH = 0;
   double sumW = 0;

   for (int i = 0; i < numPeople; i++) {
       sumH += people[i].height;
       sumW += people[i].weight;
   }
   *aveHeight = sumH / numPeople;
   *aveWeight = sumW / numPeople;

} // getAverages()
void getStandardDevs(Person people[], double aveHeight, double aveWeight, double*
   stdHeight, double* stdWeight, int numPeople)
{
   double h = 0;
   double w = 0;

   for (int i = 0; i < numPeople; i++) {
       h += pow((people[i].height - aveHeight),2);
       w += pow((people[i].weight - aveWeight),2);
   }
   h = h / numPeople;
   w = w / numPeople;
   *stdHeight = sqrt(h);
   *stdWeight = sqrt(w);
} // getStandardDevs()