GATE 2026 XH5 (Psychology) – Question 44

Research Methods and Statistics · Statistics in Psychology: Central tendency and dispersion, normal probability curve, parametric and non-parametric tests, effect size and power analysis · 1 mark · Multiple choice

Calculate the value of Standard Deviation using the following scores:

Scores: 15, 12, 14, 11, 13

$\sqrt{2}$
$\sqrt{3}$
2
1.01

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Correct answer: (A) $\sqrt{2}$

Explanation

The mean is $\frac{15 + 12 + 14 + 11 + 13}{5} = 13$. The deviations are $2, -1, 1, -2, 0$, and their squares add up to $4 + 1 + 1 + 4 + 0 = 10$. So $\sigma = \sqrt{\frac{10}{5}} = \sqrt{2}$.