To find the median, your numbers have to be listed in numerical order from smallest to largest, so you may have to rewrite your list before you can find the median. Mean, median, and mode are three kinds of "averages". Example: what is the mean of 2, 7 and 9? There are many "averages" in statistics, but these are, I think, the three most common, and are certainly the three you are most likely to encounter in your pre-statistics courses, if the topic comes up at all.The "mean" is the "average" you're used to, where you add up all the numbers and then divide by the number of numbers. The middle two numbers are The mode is the number that is repeated most often, but all the numbers in this list appear only once, so there is no mode.The values in the list above were all whole numbers, but the mean of the list was a decimal value. This list has two values that are repeated three times; namely, As you can see, it is possible for two of the averages (the mean and the median, in this case) to have the same value. Just remember the following:(In the above, I've used the term "average" rather casually. The Arithmetic Mean is the average of the numbers: a calculated "central" value of a set of numbers. But there is no "middle" number, because there are an even number of numbers. Since I don't have a score for the last test yet, I'll use a variable to stand for this unknown value: "You can use the Mathway widget below to practice finding the median. If no number in the list is repeated, then there is no mode for the list.The "range" of a list a numbers is just the difference between the largest and smallest values.The mean is the usual average, so I'll add and then divide:(13 + 18 + 13 + 14 + 13 + 16 + 14 + 21 + 13) ÷ 9 = 15Note that the mean, in this case, isn't a value from the original list. The arithmetic mean (or simply mean) of a sample $${\displaystyle x_{1},x_{2},\ldots ,x_{n}}$$, usually denoted by $${\displaystyle {\bar {x}}}$$, is the sum of the sampled values divided by the number of items in the sample To calculate it: • add up all the numbers, • then divide by how many numbers there are. To find the median, your numbers have to be listed in numerical order from smallest to largest, so you may have to rewrite your list before you can find the median. To find the average of all his grades (the known ones, plus the unknown one), I have to add up all the grades, and then divide by the number of grades. Symbol Symbol Name Meaning / definition Example; P(A): probability function: probability of event A: P(A) = 0.5: P(A ⋂ B): probability of events intersection: probability that of events A and B mean [mēn] an average; a number that in some sense represents the central value of a set of numbers. But this is Note: Depending on your text or your instructor, the above data set may be viewed as having no mode rather than having two modes, because no single solitary number was repeated more often than any other. In a list of ten values, that will be the The mode is the number repeated most often. Try the entered exercise, or type in your own exercise.