Answer:
Here is the C++ program:
#include<iostream> //to use input output functions
#include<iomanip> //to use setprecision
using namespace std; //to identify objects cin cout
int main() { //start of main function
int n1, n2, n3, n4, n5, n6, n7, min, max; // declare variables for 7 numbers, minimum value and maximum value
double sum= 0; //declare variable to hold sum of 7 numbers
double average; //declare variable to hold average of 7 numbers
cout<<"Enter first number: "; //prompts user to enter 1st number
cin>>n1; //reads first number from user
max = n1; //sets the first number to maximum
min=n1; //sets the first number to minimum
cout<<"Enter second number: "; //prompts user to enter 2nd number
cin>>n2; //reads second number from user
if(n2<min){ //if second number is less than min
min=n2; } //sets min to n2
if(n2>max){ //if n2 is greater than max
max = n2; } //sets max to n2
cout<<"Enter third number: "; //prompts user to enter 3rd number
cin>>n3; //reads third number from user
if(n3<min){ //checks if n3 is greater than min
min=n3; } //sets n3 to min
if(n3>max){ //checks if n3 is greater than max
max = n3; } //sets max to n3
cout<<"Enter fourth number: ";//prompts user to enter 4th number
cin>>n4; //reads fourth number from user
if(n4<min){ //if n4 is less than min
min=n4; } //sets min to n4
if(n4>max){ //if n4 is greater than max
max = n4; } //sets max to n4
cout<<"Enter fifth number: "; //prompts user to enter 5th number
cin>>n5; //reads fifth number from user
if(n5<min){ //if n5 is less than min
min=n5; } //sets min to n5
if(n5>max){ //if n5 is greater than max
max = n5; } //sets max to n5
cout<<"Enter sixth number: "; //prompts user to enter 6th number
cin>>n6; //reads sixth number from user
if(n6<min){ // if n6 is less than min
min=n6; } //sets min to n6
if(n6>max){ //if n6 is greater than max
max = n6; } //sets max to n6
cout<<"Enter seventh number: ";//prompts user to enter 7th number
cin>>n7; //reads seventh number from user
if(n7<min){ //if n7 is less than minimum number
min=n7; } //assigns n7 to min
if(n7>max){ //if n7 is greater than the maximum number
max = n7; } //assigns n7 to max
sum = n1+n2+n3+n4+n5+n6+n7; //adds 7 numbers
average = sum/7; //computes average of 7 numbers
cout<<"The average is: "<<fixed<<setprecision(3)<<average<<endl; //displays average value up to show 3 digits below decimal point using setprecision method of iomanip library
cout<<"The maximum number is: "<<max<<endl; //displays maximum number of 7 numbers
cout<<"The minimum number is: "<<min<<endl; //displays miimum number of 7 numbers
return 0; }
Explanation:
The program is well explained in the comments attached to each statement of program. For example if
n1 = 3
n2 = 9
n3 = 7
n4 = 6
n5 = 2
n6 = 5
n7 = 4
When n1 is read using cin then this number is set to max and min as:
min = 9
max = 3
Now when n2 is read, the first if condition checks if n2 is less than min and second if condition checks if n2 is greater than max. As n2 = 9 so it is not less than min so this if condition is false and n2 is greater than max i.e. 3 so this condition is true. So 9 is assigned to max.
min = 9
max = 9
Now when n3 is read the values of min and max become:
min = 7
max = 9
Now when n4 is read the values of min and max become:
min = 6
max = 9
Now when n5 is read the values of min and max become:
min = 2
max = 9
Now when n6 is read the values of min and max become:
min = 2
max = 9
Now when n7 is read the values of min and max become:
min = 2
max = 9
Now the statement sum = n1+n2+n3+n4+n5+n6+n7;
executes which becomes:
sum = 3 + 9 + 7 + 6 + 2 + 5 + 4
sum = 36.0
Next program control moves to statement:
average = sum/7;
this becomes
average = 36/7
5.142857
Since this is to be displayed up to 3 decimal places so average = 5.143
the complete output of the program is attached.