Arithmetic Mean

Formula

Simple Arithmetic Mean

When to use

Used when you have individual numbers — not grouped or weighted.

Formula

AM  =  Sum of all observationsNumber of observations
AM  =  x1 + x2 + x3 + ⋯ + xnn
  • x1, x2, …, xn = individual numbers
  • n = total count of numbers
Practice

Simple Arithmetic Mean

Find the Arithmetic Mean of:
Formula

Discrete Arithmetic Mean

When to use

Used when numbers have frequencies — how many times each value occurs.

Formula

AM  =  ∑ fi xi∑ fi
  • xi = value of each observation (Marks)
  • fi = frequency of xi (No. of students)
  • ∑ fi = total number of observations (N)
  • ∑ fixi = sum of all (frequency × value)

Example table structure

Marks (X) No. of Students (f) f × X
10 3 3 × 10 = 30
20 4 4 × 20 = 80
30 7 7 × 30 = 210
∑f = N = 14 ∑fX = 320
Practice

Discrete Arithmetic Mean

Given Data:
Marks No. of Students

Fill in the f×X column and the totals, then solve step by step.

Marks (X) No. of Students (f) f × X
Number Keypad
Tap a cell to select it, then enter digits. Cursor moves automatically on correct answer.