Q&A for How to Find the Median of a Set of Numbers

Subtract the lowest number in the set from the highest number.

The mode is the digit in the set that appears most often. Example: 9,7,8,2,9,3,9 -- the mode is 9.

No, just treat each occurrence as a separate piece of data and add them just like you would different numbers.

Yes, the zero counts. There are seven numbers in this sequence. The median (or middle number) of a seven-number sequence arranged in numerical order is the fourth number. In this case, that's 3.

Yes. You can have more than two, too.

Yes. Do it exactly the same way you would do it when the numbers are presented in ascending order.

The mode is the value that occurs most often in a series of numbers, so first write out the numbers in the series in numerical order, and then find the number that appears the most times. For example, if your series is 3, 7, 8, 4, 5, 3, 4, 9, 4, then you can order them as: 3, 3, 4, 4, 4, 5, 7, 8, 9. The mode is 4 because it occurs the most times (three) in the series.

"Mean" and "average" are the same thing. Add the numbers together, and divide the sum by the number of numbers added.

If every number appears only once in the set, then there is no mode. Just put "no mode".

If in a set of numbers there are 2 numbers equally repeated then both of the numbers are the mode; put them both down.

As explained in Method 2 above, the median is the average of (in this case) the fifth and sixth numbers. So you add the fifth and sixth numbers and divide by 2.

By inspection. Look for a data point that is isolated from the rest.

The median of a number set can be helpful in determining a "typical" number, sometimes more helpful than the "mean" or "average" number in the set (which could be skewed by an unrepresentative concentration of high or low numbers).

If there are two middle numbers, the median would simply be the average of the two numbers.

Yes. The first thing you do is list each of the numbers (including repeats) in either ascending or descending order. (It doesn't matter which). In this case, it would be 2 2 3 5 (or 5 3 2 2). Now find the middle number of the list. That's the median. If the list has an even number of numbers (as in this case), there will be two middle numbers, and the median is the average of those two middle numbers. In this case the median is the average of 2 and 3. (2 + 3) / 2 = 5/2 = 2½. (The median does not have to be a whole number.)

Treat the repeats the same way you would any other number: add everything together, and divide by the number of numbers (including the repeats). For example, if the data set consists of 3, 4, 5, 5, 6, 6, 7 and 8, the sum of those eight numbers is 44. Divide 44 by 8: that's 5.5, which is the mean. (A repeated number merely pulls the mean a little closer to the repeated number.)