Question 14020 – NIC-NIELIT Scientist-B 2020
November 14, 2023Question 14016 – NIC-NIELIT Scientist-B 2020
November 14, 2023Question 14019 – NIC-NIELIT Scientist-B 2020
Directions for question number 36 to 37:
Consists of a question and two statements, labelled (1) and (2), in which certain data are given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements, plus your knowledge of mathematics and everyday facts.
Q37. What is the Standard Deviation (SD) of the four numbers A, B, C, D?
Statement (1):
The sum of A, B, C and D is 24.
Statement (2):
The sum of the squares of A, B, C and D is 224.
Correct Answer: C
Question 37 Explanation:
Standard Deviation of A,B,C,D
I) Σ(A,b,C,D) = 24
II) A2 + B2 + C2 + D2 = 224
μ = 24/4 = 6
S.D = √(Σ(X-μ)2)/4
= √(A2 + μ2 – 2Aμ + B2 + μ2 -2μB + C2 + μ2 – 2μC + D62 + μ2 – 2μD) / 4
= √(A2 + B2 + C2 + D2 + 4μ2 – 2μ ( A+B+C+D)/4)
= √(224 + 4 * 24^2 – 2*24 (4*24))/4
Combining I and II
= √-808
I) Σ(A,b,C,D) = 24
II) A2 + B2 + C2 + D2 = 224
μ = 24/4 = 6
S.D = √(Σ(X-μ)2)/4
= √(A2 + μ2 – 2Aμ + B2 + μ2 -2μB + C2 + μ2 – 2μC + D62 + μ2 – 2μD) / 4
= √(A2 + B2 + C2 + D2 + 4μ2 – 2μ ( A+B+C+D)/4)
= √(224 + 4 * 24^2 – 2*24 (4*24))/4
Combining I and II
= √-808
Only Statement (1) is required for answering the question
Only Statement (2) is required for answering the question
Both Statement together are required to answer the question
Answer cannot be ascertained with the given information
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