## The **Objective of this post**, you will see various Python examples that cover the following:

**Calculate/Find**the Average of n natural numbers**using loop and range function**.- Find/Calculate Average of n natural numbers in
**python using while loop** - Python program to
**find/calculate the Average of numbers**in a given list - The mathematical formula to
**find/calculate the Average of n numbers**with python program - Python Program to Find/Calculate
**Average of n odd**natural numbers. - Python Program to Find/Calculate
**Average of n even**natural numbers.

Now let’s see each one by one:

### 1: **Find/**Calculate the **Average **of n natural numbers **using loop and range function**

- Use a python input() function in your python program that takes an input from the user to enter the number (n) to calculate the sum.
- Next, declare variables that name sum, avg. avg will contain an average of n natural numbers average.
- Next, run loop till the entered number using the for loop and range() function.
- Inside a loop, calculate the sum of n numbers using a
**sum = sum+num**formula. - Next, calculate the average of n numbers using a
**average = sum / n**formula. - After the loop ends, print the sum, avg variable that contains
**the sum , average of n numbers**

#### Python program to find the sum and average of n numbers using for loop:

n = input("Enter Number to calculate sum & average") n = int (n) sum = 0 for num in range(0, n+1, 1): sum = sum+num average = sum / n print("SUM of", n, "numbers is: ", sum ) print("Average of", n, "natural number is: ", average)

**Output**:

Enter Number to calculate sum & average 5 SUM of 5 numbers is: 15 Average of 5 natural number is: 3.0

### 2: **Find/**Calculate Sum of n natural numbers in python using while loop

Also, use the while loop in python to calculate the sum of n numbers.

- First of all, you can use a python input() function in your python program that takes input from a user to enter the number (n) to calculate the sum and average.
- Next, declare variables that name sum and avg. avg will contain the avg of n natural numbers sum.
- Run while loop until n is greater than zero
- Add the current value of n to sum variable. And, decrement n number by 1 in while loop body.
- Next, calculate the average of n numbers using a
**average = sum / n**formula. - After the loop finishes, the print sum and avg name variable.

#### Python program to find the sum and average of n numbers using While loop:

n = input("Enter Number to calculate sum and average") n = int (n) totalNo = n sum=0 while (n >= 0): sum += n n-=1 average = sum / totalNo print ("sum of ", totalNo ,"using while loop ", sum) print ("average of", totalNo ,"using while loop ", average)

**Output**:

Enter Number to calculate sum and average 5 sum of 5 using while loop 15 average of 5 using while loop 3.0

### 3: Python program to **Find/**Calculate the average and sum of numbers in a given list

- Declare a variable that name avg and sum. Avg will contain the average of n natural numbers.
- Next, define list and assign a value to a python list.
- Run for a loop and Add the current value of n to sum variable.
- Next, calculate the average of n numbers.
- After the loop finishes, the print sum name variable.

sum = 0 list = [11,4,5,7,99,10,12] for num in list: sum = sum +num average = sum / len(list) print ("sum of list element is : ", sum) print ("Average of list element is ", average )

**Output**:

sum of list element is : 148 Average of list element is 21.142857142857142

### 4: The mathematical formula to **Find/**Calculate the sum of n numbers with python program

In the above programs, you have learned how to calculate the sum of n numbers using for loop, while loop and range function.

Now, you will learn how to calculate/find sum of n numbers in python without for loop, while loop in python. **Calculate the sum directly using a mathematical formula** in python program.

The sum of the n natural number mathematical formula is = ** n * (n+1) / 2**.

In the below python program, you will learn how to use this mathematical formula is = ** n * (n+1) / 2** to find/calculate sum of n numbers in python programs.

Follow the steps:

- Take input from user in your python program using input() function.
- Convert a user inputted number to an integer using int() function.
- Calculates sum of number by using this formula
in your python program.`n * (n+1) / 2`

- Next, Calcuate average of numbers by using this formula
**average = ( n * (n+1) / 2) / n**in your python program. - After that, the print name sum variable.

n = input("Enter a number to calculate average and sum") n = int (n) sum = n * (n+1) / 2 average = ( n * (n+1) / 2) / n print("Sum of fthe irst ", n, "natural numbers using formula is: ", sum ) print("Average of the first ", n, "natural numbers using formula is: ", average )

**Output**:

Enter a number to calculate average and sum 5 Sum of fthe irst 5 natural numbers using formula is: 15.0 Average of the first 5 natural numbers using formula is: 3.0

### 5: Python Program to Find/Calculate average and sum of n odd natural numbers

- Take input from user using python input() function in your python program.
- Next, declare a variable that name sum, it will contain the sum of n odd numbers.
- Next, run loop till the entered number using the for loop and range() function.
- Inside a loop, calculate the sum of n odd numbers using a
`sum = sum + current number`

formula with (not (num % 2) == 0). - Next, calculate the average of n odd numbers.
- After the loop ends, print the sum variable that contains
**the sum of n odd numbers**.

#### Python program to find average and sum of n odd numbers:

n = input("Enter Number to calculate average and sum") n = int (n) sum = 0 for num in range(0, n+1, 1): if(not (num % 2) == 0): sum += num; average = sum / n print("SUM of odd numbers is: ", sum ) print("Average of odd numbers is: ", average )

**Output**:

Enter Number to calculate sum 5 SUM of odd numbers is: 9

### 6: Python Program to Find/Calculate average and sum of n even natural numbers

- Take input from the user using python input() function in your python program.
- Next, declare a variable that name sum, it will contain the sum of n even numbers.
- Next, run loop till the entered number using the for loop and range() function.
- Inside a loop, calculate the sum of n even numbers using a
`sum = sum + current number`

formula with if test condition ((num % 2) == 0). - Next, calculate the average of n even numbers.
- After the loop ends, print the sum variable that contains
**the sum of n even numbers**.

#### Python program to find average and sum of n even numbers:

n = input("Enter Number to calculate average and sum") n = int (n) sum = 0 for num in range(0, n+1, 1): if((num % 2) == 0): sum += num; average = sum / n print("SUM of even numbers is: ", sum ) print("Average of even numbers is: ", average )

**Output**:

Enter Number to calculate average and sum 5 SUM of even numbers is: 6 Average of even numbers is: 1.2