The provided code reads in data from a file and stores it in a vector named signal. Three functions prototypes are declared at the top named mean, stdev, and median.
Define these functions to calculate the mean, standard deviation, and median of the values in the signal vector.

#include
using namespace std;
// Function prototypes. You must define these functions after main().
double mean( vector &sig );
double stdev( vector &sig );
double median( vector &sig );

int main(){
// create object to read in data
ifstream inFile;
double mean( vector &sig ){
// Fill in function definition
// The vector sig is in scope here, so you can use it
// Return the mean value
}

double stdev( vector &sig ){
// Fill in function definition
// The vector sig is in scope here, so you can use it
// Return the stdev
}

double median( vector &sig ){
// Fill in function definition
// The vector sig is in scope here, so you can use it
// Return the median value
}
// read in filename
string fname;
cout << "Provide an input file name: " << endl;
cin >> fname;

// open file and confirm that it is open
inFile. open(fname);
if (!inFile. is_open()){
cout << "Could not open file " << fname << "." << endl;
return -1;
}

// read in numbers from file and store in a vector
vector signal(0);
while( !inFile. eof() ){
double tmp;
inFile >> tmp;
signal. push_back( tmp );
}
signal. pop_back();

printf(" Average: %lf\n", mean( signal ));
printf("Standard deviation: %lf\n", stdev( signal ));
printf(" Median: %lf\n", median( signal ));

// close file
inFile. close();

return 0;
}