Answer:
The complete method in cpp is given below.  
void printPopcornTime(int bagOunces)  
{  
if(bagOunces<2)  
cout<<"Too small"<<endl;  
else if(bagOunces>10)  
cout<<"Too large"<<endl;  
else  
cout<<6*bagOunces << " seconds"<<endl;  
}  
The program implementing the above method is given below.  
#include <iostream>  
using namespace std;  
//method declared  
void printPopcornTime(int bagOunces);  
int main() {  
//variable declared  
int bagOunces;  
//variable initialized  
bagOunces = 10;  
//method called which accepts integer parameter  
printPopcornTime(bagOunces);  
//program ends  
return 0;  
}  
//method defined  
void printPopcornTime(int bagOunces)  
{  
//output displayed based on the value of the variable  
if(bagOunces<2)  
cout<<"Too small"<<endl;  
else if(bagOunces>10)  
cout<<"Too large"<<endl;  
else  
cout<<6*bagOunces << " seconds"<<endl;  
}  
OUTPUT1  
60 seconds  
Explanation:
Program explanation is given below.
1. The method, printPopcornTime(), having return type as void and accepting an integer parameter, bagOunces, is declared as shown.  
void printPopcornTime(int bagOunces);  
2. Method declaration only contains return type, method name and parameters taken by the method, if any.  
3. Method definition consists of the complete method. All the code to be written inside the method is also included in its definition.  
4. The method definition for printPopcornTime() is shown in the beginning.  
5. The value of the integer parameter is tested using multiple if-else statements.  
6. The output is based on the value of the parameter. The output is ends with a newline inserted by endl.
7. The main() method has a return type integer and takes no parameters. The main() method is declared and defined together unlike as shown for the other method, printPopcornTime().  
8. The integer variable, bagOunces, is declared and initialized inside main().  
9. This variable is passed as parameter to the printPopcornTime() method and calling the method.  
printPopcornTime(bagOunces);  
10. The program ends with a return statement.  
11. All the results are shown based on the different values of the variable, bagOunces. The original output is obtained when the value of bagOunces is 10.  
12. If the value of bagOunces is 1, the message displayed is shown.  
OUTPUT2  
Too small  
13. If the value of bagOunces is 11, the message displayed is shown.  
OUTPUT3  
Too large