It might be easier to calculate the mean and median if we rearrange the numbers first.
Mean: 14 centimeters Median: 14 centimeters
Practice makes perfect
We want to find the mean and median for the lengths of the bodies of jumping frogs. The first thing to do when finding the key features of a data set is rearranging the numbers from least to greatest. Let's do it!
20.3, 12.5, 7.6, 13.9, 9.2, 21.7 7.6, 17.5, 15.6, 14.1
⇓
7.6, 7.6, 9.2, 12.5, 13.9, 14.1 15.6, 17.5, 20.3, 21.7
Let's find the mean and median now.
Mean
The mean of a data set is calculated by finding the sum of all values in the set and then dividing it by the number of values in the set. In this case, there are 10 values in the set, so we will divide the sum of the data set by 10.
To identify the median, we look at the middle value.
7.6, 7.6, 9.2, 12.5, 13.9 | 14.1 15.6, 17.5, 20.3, 21.7
Dang it! There is no middle value. When this happens, we calculate the median by finding the average of the two values closest to the middle. When arranged from least to greatest, 13.9 and 14.1 are the most central values, so let's find the average of these numbers.
Median=13.9+ 14.1/2=14
The median of the data set is also 14 centimeters.
