Find the median, mean, and mode of the following set of data: 55, 43, 62, 91, 2, 43, 34, 16, 16.

To find the median, we first need to rewrite the set of data in ascending order of values: 2, 16, 16, 34, 43, 43, 55, 62, 91. We then count how many items are in this list. The median is the item in the middle position of this list. There are 9 items in this list. If there is an odd number of items, as there is in this question, we need to add 1 to the total number of items, and then halve this to find the position of the median. (9+1)/2=5 so we look for the 5th number in the list, which is 43. If the number of items in the list was even, we would have just halved the total and found this position (so with a list of 16 items, the median is the 16/2=8th item in the list).

To find the mean of the set of data, we add up all of the values and divide this by the number of items. The total of the values is 55+43+62+91+2+43+34+16+16=362. To find the mean, we divide this by the number of items in the list, 9. The mean is therefore 362/9=40.22(recurring).

The mode of a set of data is the item(s) that appear the most often. For example, 55 only appears once in the set of data, 19 doesn't appear at all, but 43 appears twice. Therefore 43 is a mode. There can be more than one mode, as long as the modes appear an equal amount of times. 16 also appears twice, and no other value in the set of data appears more than once, so 43 and 16 are the modes.