Final answer:
The correct statement is d.
All of the above are true.
Step-by-step explanation:
The correct statement from the given options is d. All of the above are true.
The normal distribution is a commonly observed pattern in many disciplines. It is bell-shaped and can be described by its mean and the variation of actual demand about the mean.
In a symmetrical distribution, the mean and the median are both centrally located close to the high point of the distribution. This is the case in a normal distribution.