Paper: CSIR-NET December 2013 · Subject: Physical Chemistry · Chapter: Data Analysis · Topic: Error Propagation · Marks: 2 · Difficulty: Medium
The masses recorded when a substance is weighed 4 times are 15.8, 15.4, 15.6 and 16.0 mg. The variance (square of the standard deviation) is closest to
(a)0.02
(b)0.05
(c)0.10
(d)0.20
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
Mean 15.7; squared deviations 0.01, 0.09, 0.01, 0.09 sum to 0.20; variance = 0.20/4 = 0.05 (0.067 with n − 1) — closest to 0.05.