The below workout with step by step calculation shows how to find what is the average of numbers from 400 to 800 manually.
step 1 Address the formula and input values.
Formula: Average = Total Sum of Numbers / Total Count of Numbers
Input values:
The numbers from 400 to 800 are
400, 401, 402, 403, . . . . , 798, 799, 800
Total Count of Numbers = 401
step 2 Find the sum of numbers from 400 to 800.
sum = 400 + 401 + 402 + . . . . + 799 + 800
= 240600
step 3 Divide the sum by 401
Average = 240600/401
= 600
600 is an average of numbers from 400 to 800.