[Solved] The last supernova in the Milky Way Galaxy that was visible to the naked eye was observed when? A) Astronomers have never seen a naked-eye supernova. B) They are quite common, so one was observed within the last year. C) There are reports of a supernova eruption in 1066. D) Kepler observed one in 1604. Mean: The average of a set of values, calculated by summing all the values and then dividing by the count of values. Normally Distributed: Refers to a statistical distribution that is balanced around the mean, indicating that values close to the mean occur more often than those far from the mean. Mean: The mean is the average of a set of numbers, calculated by dividing the sum of these numbers by their count. Normally Distributed: Describes a distribution that follows a bell-shaped curve, where the mean, median, and mode are equal; commonly used in probability and statistics.