A normal distribution is completely described by what? A) Its mean. B) Its standard deviation. C) Its mean and standard deviation. D) none of the above.

A normal distribution is completely described by its mean and standard deviation! The mean indicates the center of the distribution, while the standard deviation tells you how spread out the values are. Together, these two parameters shape the familiar bell curve, ensuring that approximately 68% of the data falls within one standard deviation of the mean. In the real world, normal distributions pop up everywhere—from heights and weights of a population to test scores. Understanding these distributions helps in various fields, including psychology and quality control in manufacturing, where making sense of natural variations is crucial. So, whether you're measuring how well students do on a test or analyzing product defects, the normal distribution is your trusty sidekick!