The mean is the average of a data set. The mode is the most common number in a data set. The mean means average. To find it, add together all of your values and divide by the number of addends. The median is the middle number of your data set when in order from least to greatest. The mode is the number that occurred the most often.
The median is the middle of the set of numbers. The median is the middle number in a sorted, ascending or descending, list of numbers and can be more descriptive of that data set than the average. Median is sometimes used as opposed to the mean when there are outliers in the sequence that might skew the average of the values. Chapter 34 describes finding the mean and median for a given set of numbers, with examples.
The middle number; found by ordering all data points and picking out the one in the middle (or if there are two middle numbers, taking the mean of those two numbers). Example: The median of 4, 1, and 7 is 4 because when the numbers are put in order (1, 4, 7), the number 4 is in the middle.