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Can the standard deviation have a negative value? Explain.

Short Answer

Expert verified
No, the standard deviation cannot be negative. Given the mathematical operations involved in its calculation (squares and square roots), all resulting values must be either zero or positive.

Step by step solution

01

Understand the question

The goal is to determine whether the standard deviation, a statistical measure, can ever be negative. The standard deviation measures the amount of variation or dispersion of a set of values.
02

Recall the formula for standard deviation

The calculation for standard deviation is: \( \sigma = \sqrt{\frac{1}{N} \sum_{i=1}^N (x_i - \mu)^2 }\) where \( \sigma \) is the standard deviation, \( N \) is the size of the sample, \( x_i \) are the individual data points, and \( \mu \) is the mean of the data set.
03

Explain why standard deviation can't be negative

In the formula for standard deviation, \( (x_i - \mu)^2 \) ensures that each term is non-negative because the square of any real number, whether negative or positive, is always non-negative. The sum of non-negative numbers is also non-negative, and the square root of a non-negative number is also non-negative. So, the standard deviation can never be negative since all the operations and terms involved in its calculation can never result in a negative number.

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Most popular questions from this chapter

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