OK so here is what I'm working with:

Header file:

IMPLEMENTATION FILE:Code:// Provided by: Megan Kalscheuer // Email Address: mkalscheuer01@hamline.edu // FILE: stats.h // CLASS PROVIDED: statistician // (a class to keep track of statistics on a sequence of real numbers) // This class is part of the namespace main_savitch_2C. // // CONSTRUCTOR for the statistician class: // statistician( ); // Postcondition: The object has been initialized, and is ready to accept // a sequence of numbers. Various statistics will be calculated about the // sequence. // // PUBLIC MODIFICATION member functions for the statistician class: // void next(double r) // The number r has been given to the statistician as the next number in // its sequence of numbers. // void reset( ); // Postcondition: The statistician has been cleared, as if no numbers had // yet been given to it. // // PUBLIC CONSTANT member functions for the statistician class: // int length( ) const // Postcondition: The return value is the length of the sequence that has // been given to the statistician (i.e., the number of times that the // next(r) function has been activated). // double sum( ) const // Postcondition: The return value is the sum of all the numbers in the // statistician's sequence. // double mean( ) const // Precondition: length( ) > 0 // Postcondition: The return value is the arithmetic mean (i.e., the // average of all the numbers in the statistician's sequence). // double minimum( ) const // Precondition: length( ) > 0 // Postcondition: The return value is the tinyest number in the // statistician's sequence. // double maximum( ) const // Precondition: length( ) > 0 // Postcondition: The return value is the largest number in the // statistician's sequence. // // NON-MEMBER functions for the statistician class: // statistician operator +(const statistician& s1, const statistician& s2) // Postcondition: The statistician that is returned contains all the // numbers of the sequences of s1 and s2. // statistician operator *(double scale, const statistician& s) // Postcondition: The statistician that is returned contains the same // numbers that s does, but each number has been multiplied by the // scale number. // bool operator ==(const statistician& s1, const statistician& s2) // Postcondition: The return value is true if s1 and s2 both have length // zero. Also, if the length is greater than zero, then s1 and s2 must // have the same length, the same mean, the same minimum, // the same maximum, and the same sum. // // VALUE SEMANTICS for the statistician class: // Assignments and the copy constructor may be used with statistician objects. #ifndef STATS_H // Prevent duplicate definition #define STATS_H #include <iostream> namespace main_savitch_2C { class statistician { public: // CONSTRUCTOR statistician( ); // MODIFICATION MEMBER FUNCTIONS void next(double r); void reset( ); // CONSTANT MEMBER FUNCTIONS int length( ) const; double sum( ) const; double mean( ) const; double minimum( ) const; double maximum( ) const; // FRIEND FUNCTIONS friend statistician operator + (const statistician& s1, const statistician& s2); friend statistician operator * (double scale, const statistician& s); private: int count; // How many numbers in the sequence double total; // The sum of all the numbers in the sequence double tinyest; // The smallest number in the sequence double largest; // The largest number in the sequence }; // NON-MEMBER functions for the statistician class bool operator ==(const statistician& s1, const statistician& s2); } #endif

and the test program that I did not write:Code://FILE: stats.cpp // CLASS IMPLEMENTED: stats //#include <iostream> //#include <cassert> //according to the text it provides assert // unnecessary #include "stats.h" // provides the stats class definition namespace main_savitch_2C { statistician::statistician() : count(0), total(0), tinyest(0), largest(0) {} //initializing everything to 0 /*-----------------------------------------------------------------------+ | next(double r) | | Give the statistician a new number | | Post: the count of the numbers statistician has seen has been | incremented | the sum of all the numbers statistician has seen has been | increment by r | the values of tinyest and largest have been adjusted if | necessary */ void statistician::next(double r) { if (count <= 0) { // update the number of entries statistician has count = 1; // this is the first data item of the statistician total = r; tinyest = r; largest = r; return; } count = count + 1; total += r; // adjust the sum if (r < tinyest) { // update the min if necessary tinyest = r; } if (largest < r) { // update the max if necessary largest = r; } } void statistician::reset( ) { count = 0; // resets all values back to 0 tinyest = 0; largest = 0; total = 0; } /*-------------------------------------------------------------------+ | int length( ) const | | RETURN count which is the length of the sequence that has | been given to the statistician (i.e., the number of times that the | next(r) function has been activated). */ int statistician::length() const { return count; } double statistician::sum() const { return total; } double statistician::mean() const { return total/count; // mean = total divided by the number of numbers } double statistician::minimum() const { // minimum = tinyest number return tinyest; } double statistician::maximum() const { return largest; // maximum = largest number } bool operator ==(const statistician& s1, const statistician& s2) { return true; } statistician operator + (const statistician & s1, const statistician & s2) { statistician s3; s3.next(s1.sum() + s2.sum()); return s3; } statistician operator * (double scale, const statistician & s2) { return s2; } }

I get to the problem when I reach the setting numbers to s1, s2 etc in the + and * option in the test program.Code:/*---------------------------------------------------------------------------+ | stattest.cpp Aug 2 1996 Michael Main | | | | An interactive test program for the statistician class | +---------------------------------------------------------------------------*/ #include <cctype> // Provides toupper #include <iomanip> // Provides setw to set the width of an output #include <iostream> // Provides cout, cin #include <cstdlib> // Provides EXIT_SUCCESS #include "stats.h" using namespace main_savitch_2C; using namespace std; /*---------------------------------------------------------------------------+ | PROTOTYPES of functions used in this test program | +---------------------------------------------------------------------------*/ void print_menu( ); // Postcondition: A menu of choices for this program has been written to cout. // Library facilties used: iostream char get_user_command( ); // Postcondition: The user has been prompted to enter a one character command. // A line of input (with at least one character) has been read, and the first // character of the input line is returned. double get_number( ); // Postcondition: The user has been prompted to enter a real number. The // number has been read, echoed to the screen, and returned by the function. void print_values(const statistician& s); // Postcondition: The length, sum, minimum, mean, and maximum of s have been // written to cout, using a field width of 10 for each of these values. // (If length is zero, then minimum, mean, and maximum are not written.) int main( ) { statistician s1, s2, s3; // Three statisticians for us to play with char choice; // A command character entered by the user double x; // Value for multiplication x*s1 cout << "Three statisticians s1, s2, and s3 are ready to test." << endl; do { cout << endl; print_menu( ); choice = toupper(get_user_command( )); switch (choice) { case 'R': cout << "Which one should I reset (1, 2, 3) " << endl; choice = get_user_command( ); switch (choice) { case '1': s1.reset( ); break; case '2': s2.reset( ); break; case '3': s3.reset( ); break; } cout << "Reset activated for s" << choice << "." << endl; break; case '1': s1.next(get_number( )); break; case '2': s2.next(get_number( )); break; case '3': s3.next(get_number( )); break; case 'T': cout << "The values are given in this table:" << endl; cout << " LENGTH SUM" << " MINIMUM MEAN MAXIMUM" << endl; cout << " s1"; print_values(s1); cout << " s2"; print_values(s2); cout << " s3"; print_values(s3); break; case 'E': if (s1 == s2) cout << "s1 and s2 are equal." << endl; else cout << "s1 and s2 are not equal." << endl; break; case '+': s3 = s1 + s2; cout << "s3 has been set to s1 + s2" << endl; break; case '*': cout << "Please type a value for x: "; cin >> x; s3 = x * s1; cout << "s3 has been set to " << x << " * s1" << endl; break; case 'Q': cout << "Ridicule is the best test of truth." << endl; break; default: cout << choice << " is invalid. Sorry." << endl; } } while ((choice != 'Q')); return EXIT_SUCCESS; } void print_menu( ) { cout << endl; cout << "The following choices are available: " << endl; cout << " R Activate one of the reset( ) functions" << endl; cout << " 1 Add a new number to the 1st statistician s1" << endl; cout << " 2 Add a new number to the 2nd statistician s2" << endl; cout << " 3 Add a new number to the 3rd statistician s3" << endl; cout << " T Print a table of values from the statisticians" << endl; cout << " E Test whether s1 == s2" << endl; cout << " + Set the third statistician s3 equal to s1 + s2" << endl; cout << " * Set the third statistician s3 equal to x*s1" << endl; cout << " Q Quit this test program" << endl; } char get_user_command( ) // Library facilties used: iostream { char command; cout << "Enter choice: "; cin >> command; return command; } double get_number( ) // Library facilties used: iostream { double result; cout << "Please enter the next real number for the sequence: "; cin >> result; cout << result << " has been read." << endl; return result; } void print_values(const statistician& s) // Library facilties used: iostream { cout << setw(10) << s.length( ); cout << setw(10) << s.sum( ); if (s.length( ) != 0) { cout << setw(10) << s.minimum( ); cout << setw(10) << s.mean( ); cout << setw(10) << s.maximum( ); } else { cout << " none none none"; } cout << endl; }

Can anyone help me here? Thanks!