RRB Technician Grade I 13 March 2026 Paper

Concept:Standard deviation measures the spread of data from the mean.Explanation:For each group, first find the mean, then compute the standard deviation.$SD = \sqrt{\frac{\sum(x - \text{mean})^2}{n}}$A. Entire dataset: $48, 50, 52, 55, 60, 65$Mean $= \frac{330}{6} = 55$Sum of squared deviations $= 49 + 25 + 9 + 0 + 25 + 100 = 208$$SD = \sqrt{\frac{208}{6}} = \sqrt{34.67} \approx 5.88$ — matches I.B. Middle four values: $50, 52, 55, 60$Mean $= \frac{217}{4} = 54.25$Sum of squared deviations $= 18.0625 + 5.0625 + 0.5625 + 33.0625 = 56.75$$SD = \sqrt{\frac{56.75}{4}} = \sqrt{14.1875} \approx 3.77$ — matches II.C. First three values: $48, 50, 52$Mean $= \frac{150}{3} = 50$Sum of squared deviations $= 4 + 0 + 4 = 8$$SD = \sqrt{\frac{8}{3}} = \sqrt{2.67} \approx 1.63$ — matches IV.D. Last three values: $55, 60, 65$Mean $= \frac{180}{3} = 60$Sum of squared deviations $= 25 + 0 + 25 = 50$$SD = \sqrt{\frac{50}{3}} = \sqrt{16.67} \approx 4.08$ — matches III.Therefore, A → I, B → II, C → IV, D → III.Answer:Option (1): A → I, B → II, C → IV, D → III.