In introductory statistics, which symbol is most commonly used to represent the (population) standard deviation?

• A. $\mu$
• B. ${\sigma }^2$
• C. $s$
• D. $\sigma$

Answer: (D)

Verified step by step guidance

1. Understand that the problem asks for the symbol most commonly used to represent the population standard deviation in introductory statistics.
2. Recall that the population mean is denoted by the Greek letter \( \mu \), which is not related to standard deviation.
3. Recognize that \( s \) is typically used to represent the sample standard deviation, not the population standard deviation.
4. Note that \( \sigma^2 \) represents the population variance, which is the square of the population standard deviation.
5. Conclude that the population standard deviation is represented by the Greek letter \( \sigma \), which is the square root of the population variance.