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Random Variables, Expectation & Variance · Question 54 of 68

Question 54

EasyOriginal question

The variance of a random variable is 2.25. What is its standard deviation?

1.125

Correct answerYour answer

1.5

Correct answerYour answer

2.25

Correct answerYour answer

5.0625

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer B

Correct answer: B

The standard deviation is the square root of the variance.
$\sqrt{2.25} = 1.5$ .

Worth noting

1.125 halves the variance instead of taking its square root.

Concept: The standard deviation
Typical timeTypical: 60 s
Your timeYours: —

The rule this testsVariance and standard deviation

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