A histogram tells you how many items fall into each of several bins. The median is the middle item or the average of the two middle items. 1. Find the total number of items represented by the histogram 2. Determine if that number is even or odd. Determine the number of the middle item. 3. Find the bin(s) containing the middle item(s). Example 1 Here is a histogram of test scores, with the number in each bin appended. 51-60 xxx (3) 61-70 xxxxxx (6) 71-80 xxxxxxxx (8) 81-90 xxxx (4) 91-100 xx (2) The total number of scores is 3+6+8+4+2 = 23. Half* the scores (232 = 11) are below the 12th score. The 12th score is in the 71-80 bin, so the median is 71-80. You could use 75 1/2 as a value representative of the bin values if you need to express the result as a single number. Example 2 Suppose the above histogram had (13) in the 91-100 bin. Now there are 34 total scores, of which two are in the middle. The median is on the boundary between the 71-80 bin and the 81-90 bin. You could say the median is 80 1/2.
* When we say half the scores are below the median, we really mean that there are as many scores above the median as there are below the median. In this example, we have 11 scores above the 12th score, and 11 scores below the 12th score. The backslash symbol () is sometimes uses to indicate the integer portion of the result of division. 52 = 2; 5/2 = 2.5
* When we say half the scores are below the median, we really mean that there are as many scores above the median as there are below the median. In this example, we have 11 scores above the 12th score, and 11 scores below the 12th score. The backslash symbol () is sometimes uses to indicate the integer portion of the result of division. 52 = 2; 5/2 = 2.5
