complete the member function ( fdeviation(….)) of class Stats :

Question

#include <iostream>

#include <cmath>

using namespace std;

class Stats

{ double mean, deviation;

public:

/** Function for computing mean of an array of double values */

double findmean(double x[], int size)

{

double sum = 0;

for (int i = 0; i < size; i++)

sum += x[i];

mean = sum * 1.0 / size;

return mean;

}

/** Function for computing deviation of double values */

double fdeviation(double x[], int size)

{

// this is to be completed

}

};

class DOO5441_cw_10

// this class is to keep marks and statistics for 10 students

{ double marks[10];

Stats s;

public:

void set()

{

cout << "Enter 10 marks: ";

for (int i = 0; i < 10; i++)

{

cin >> marks[i];

}

}

void printstats()

{ cout << "The mean is " <<s.findmean(marks, 10)<<endl;

cout << "The standard deviation is " << s.fdeviation(marks, 10) << endl;

}

};

int main()

{ DOO5441_cw_10 ob;

ob.set();

ob.printstats();

return 0;

}

Answer 1

/** Function for computing deviation of double values */

double fdeviation(double x[], int size)

{

// this is to be completed

double sumXSqr = 0;

for (int iLoop=0; iLoop<size; iLoop++)

{

sumXSqr = sumXSqr + x[iLoop]*x[iLoop];

}

double meanAvg = this->findmean(x,size);

return(

sqrt(

(sumXSqr - size * meanAvg*meanAvg)/(size-1)

)

);

}

};