Which of the following characteristics does not describe a normal distribution?

• A. It has two distinct peaks.
• B. Its spread is determined by the $\mathrm{standard\; deviation}$.
• C. The $\mathrm{mean}$, $\mathrm{median}$, and $\mathrm{mode}$ are all equal.
• D. It is perfectly symmetrical about the $\mathrm{mean}$.

Answer: (A)

Verified step by step guidance

1. Recall the key characteristics of a normal distribution: it is symmetric, unimodal (has one peak), and the mean, median, and mode are all equal.
2. Understand that the spread of a normal distribution is determined by the standard deviation, which measures how data points are dispersed around the mean.
3. Recognize that a normal distribution is perfectly symmetrical about its mean, meaning the left and right sides are mirror images.
4. Identify that having two distinct peaks means the distribution is bimodal, which contradicts the unimodal nature of a normal distribution.
5. Conclude that the characteristic 'It has two distinct peaks' does not describe a normal distribution because normal distributions have only one peak.