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Showing 1 question in Mathematics for Class 9. Tap a card to reveal the answer.
MathematicsStatisticseasyFind the mean of the data: 10, 15, 20, 25, 30.
Reveal answer ↓
What it is
The mean (average) is the total of all values divided by how many values there are.
Answer
Mean = (sum of all observations) / (number of observations) = (10 + 15 + 20 + 25 + 30) / 5 = 100 / 5 = 20.
Mean = (sum of observations) / (number of observations)
- •Mean = sum of values / number of values
- •Sum = 100, count = 5
- •Mean = 20
Why learn this
It summarises data in one number - used in marks, cricket averages, economics and science.
💡 Memory trick
Add them all up, divide by how many. Mean = sum / count.