The standard deviation of 100 observations is 10. If 20 is added to...

The standard deviation of 100 observations is 10. If 20 is added to each observation, then what will be the new standard deviation?

Options

A $10$
B $15$
C $20$
D $25$

Correct answer

A. $10$

Step-by-step solution

The standard deviation of a set of observations is independent of the change of origin.

If a constant is added to or subtracted from each observation, the standard deviation remains unchanged.

Given that the original standard deviation is

10

.

When

20

is added to each observation, the new standard deviation will still be

10

.

Answer:

10

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