Question

The thickness of a glass plate is measured to be 2.17 mm, 2.17 mm and 2.18 mm at three different places. Find the average thickness of the plate from this data.

Answer 1

\[\text{ Average thickness} = \frac{2 . 17 + 2 . 17 + 2 . 18}{3}\]
= 2 . 1733 mm
∴ Rounding off to three significant digits, the average thickness becomes 2.17 mm.