Mean, Median, Mode of {4, 7, 3, 7, 9}
Five friends scored points in a game. Let's find the center of their scores three different ways.
Here are the scores: four, seven, three, seven, and nine.
First, the mean. The mean is the average — we add all the numbers, then divide.
Four plus seven plus three plus seven plus nine equals thirty.
Now divide thirty by five, because there are five scores. Thirty divided by five is six.
Next, the median. The median is the middle number — but first we have to put the data in order.
Sorted from least to greatest: three, four, seven, seven, nine.
The middle value is seven. That's our median.
Last, the mode. The mode is the number that appears most often.
Seven shows up twice — every other number shows up just once. So the mode is seven.
Quick tip: if one score were huge, like ninety, the mean would jump way up, but the median would barely move. The median resists outliers!
Mean six, median seven, mode seven. Three ways to describe the center of our data!