Four persons measure the length of a rod as 20.00 cm, 19.75 cm, 17.01 cm and 18.25 cm. The relative error in the measurement of average length of the rod is :
- 0.18
- 0.24
- 0.06
- 0.08
Answer
(3) 0.06
Solution
Mean length l = 20.00 + 19.75 + 17.01 + 18.254 = 75.014 = 18.75 cm
Absolute errors: | li| = 1.25, 1.00, 1.74, 0.50 cm
Mean absolute error l = 1.25 + 1.00 + 1.74 + 0.504 = 4.494 1.12 cm
Relative error = l l = 1.1218.75 0.06
Answer: (3)