Question

The arithmetic mean of three measurements, 15.4 cm, 15.4 cm, and 15.5 cm, is 15.43 cm. How many significant figures does this result have?

Options

• 2

• 4

• 3

• 5

Answer 1

3

Explanation: 

The significant figures are 1, 5, and 4. The digits 1 and 5 are certain, while 4 is the first uncertain digit. Together, these form 3 significant figures. The last digit (3) is beyond the instrument's least count and is not counted.