Given, height (data) of 15 boys of a class are
128, 144, 146, 143, 136, 142, 138, 129, 140, 152, 144, 140, 150, 142, 154.
Arranging the given data in ascending order, we have
128, 129, 136, 138, 140, 140, 142, 142, 143, 144, 144, 146, 150, 152, 154,
Here, highest observation = 154 and lowest observation =128
∴ Range = Highest observation - Lowest observation = 154 - 128 = 26 cm