What is the average of even numbers from 21 to 81? Here we will show you how to calculate the average of even numbers from 21 to 81.
To find the average of the even numbers from 21 to 81, we first calculate how many even numbers there are from 21 to 81. Then, we calculate the sum of even numbers from 21 to 81. And finally, we divide the sum by the number of even numbers to get the average.
The range is from 21 to 81, and the even numbers within that range are from 22 to 80. Therefore, the first even number in the sequence is 22, and the last even number in the sequence is 80.
Step 1) Calculate the total number of even numbers from 21 to 81
Here we calculate the total number of even numbers from 21 to 81 by entering the first and last even number in the sequence into our formula. Here is the formula and the math:
tot = (last - first + 2) ÷ 2
tot = (80 - 22 + 2) ÷ 2
tot = 60 ÷ 2
tot = 30
Total even numbers from 21 to 81 = 30
Step 2) Calculate the sum of even numbers from 21 to 81
To calculate the sum of even numbers from 21 to 81, you enter the total even numbers (tot) from Step 1 and the first even number in the sequence into our formula. Here is the formula and the math:
sum = (tot ÷ 2) × (2 × first + (2 × (tot - 1))
sum = (30 ÷ 2) × (2 × 22 + (2 × (30 - 1))
sum = 15 × (44 + 58)
sum = 15 × 102
sum = 1530
Sum of even numbers from 21 to 81 = 1530
Step 3) Calculate the average of even numbers from 21 to 81
Almost done! Now we can calculate the average of even numbers from 21 to 81 by dividing the sum of even numbers from Step 2 by the total even numbers from Step 1. Here is the formula, the math, and the answer:
Average = sum ÷ tot
Average = 1530 ÷ 30
Average = 51
Average of even numbers from 21 to 81 = 51
Average of Even Numbers Calculator
Here you can calculate the average of even numbers of a different sequence.