Mean

Median

The median is in the middle of the ordered list of data. If finding the median by hand, first put the data in either low-to-high or high-to-low order. 

If there is an odd number of data, then the median is the middle number. For example, given the data 15 25 12 16 30, list the data in order from lowest to highest: 12 15 16 25 30. The median is the middle number, so the median = 16.

If there is an even number of data, then the median is the mean of the two middle numbers. For example, given the data 38 30 56 49 80 77, list the data in order from lowest to highest: 30 38 49 56 77 80. There are two middle numbers, so the median is the mean of 49 and 56, which is (49 + 56) / 2 = 105 / 2 = 52.5.

ALEKS Calculator Buttons

Click 'Send data to calculator' and use the first button in the third row.

This button sorts the data set from least to greatest.

Mode

The mode is the number or numbers that appear the most in the set of data.

There could be no mode, one mode, two modes, or more.

For example, given the data 44 68 76 33 27 11 25, each value appears only once, so there is not a number or numbers that appear more than the others, so there is no mode.

For example, given the data 21 36 24 78 45 30 21 45 21, the value 45 appears twice, the value 21 appears three times, the rest appear only once each, so there is one mode, 21.

For example, given the data 52 45 60 25 33 60 72 52 39, the value 52 appears twice, the value 60 appears twice, the rest appear only once each, so there are two modes, 52 and 60.

Note: For larger data sets, it is easier to see the mode if the data are in order, say low to high.