GATE Overflow Test Series | Mock GATE | Test 5 | Question: 3

Question

The average performance of the students were poor in an examination and the organizing committee decided to give extra marks of $5$ to everyone. Which of the following statistical measures will not change even after the extra marks are given?

• A. Mode
• B. Median
• C. Mean
• D. Standard deviation

Answer 1

Variance is independent of change of origin and standard deviation is its sqare root.

So, the correct answer is $(D).$

Comments

sir how does median and mode change. please give a small example

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let the original numbers be $1,1,2,2,3,4$ and $5$

median = $2$
mode = $1$ and $2$ (Bimodal)
after adding $5$, numbers become – $6 , 6 , 7 ,7, 8 , 9$ and $10$
now, median = $7$
mode = $6$ and $7$