alleryStart learning →The **standard deviation** of $X \sim B(n, p)$ is:
- $\sqrt{np}$
- $np$
- $\sqrt{npq}$
- $npq$
Show answer and solution
Correct answer: C. $\sqrt{npq}$
$SD(X) = \sigma = \sqrt{\text{Var}(X)} = \sqrt{npq}$.
UPCET / UPSEE Standard Deviation — practice questions
Explore 2 free Standard Deviation questions in UPCET / UPSEE Mathematics. Open each question or exercise to read its content, reference answers and available explanation.
Practise Standard Deviation with Quill →Standard Deviation questions and exercises with answers
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Worked practice questions
A die is thrown 100 times; 'even number' is success. The standard deviation of the number of successes is:
- $\sqrt{50}$ ≈ 7.07
- 5
- 25
- 10
Show answer and solution
Correct answer: B. 5
$p = 1/2, q = 1/2, n = 100$.
$SD = \sqrt{npq} = \sqrt{100 \cdot 1/2 \cdot 1/2} = \sqrt{25} = 5$.
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