Let's look at the data the wildlife manager collected of crocodile lengths.
2.4 2.5 2.5 2.3
2.8 2.4 2.3 2.4
2.1 2.2 2.5 2.7
To make things easier, let's write the values in order from least to greatest.
2.1 2.2 2.3 2.3
2.4 2.4 2.4 2.5
2.5 2.5 2.7 2.8
We are told that the estimation for the growth of the crocodiles is about 0.1 meters each year. Therefore, the crocodiles will grow about 0.4 meters after four years. We can change the data set to an estimate for 4 years later by adding 0.4 to every value in the set before finding the measures of central tendency.
2.5 2.6 2.7 2.7
2.8 2.8 2.8 2.9
2.9 2.9 3.1 3.2
Let's find the mean of the data. To do that we need to add every value and divide by the number of values. Let's add every value.
& 2.5 +2.6 + 2.7 + 2.7 +
& 2.8 + 2.8 + 2.8 + 2.9 +
& 2.9 + 2.9 +3.1 + 3.2 = 33.9
Since there are 12 values in the set, we need to divide the sum of every value by 12 to find the mean.
Mean: 33.9/12=2.825
The mean of the lengths of the crocodiles after four years is about 2.8m. To find the median, we need to look for the value in the middle. Since there are 12 values, we need to look at the two middle values.
2.5 2.6 2.7 2.7
2.8 2.8 2.8 2.9
2.9 2.9 3.1 3.2
Since both values in the middle are 2.8, the median of the set is 2.8m. To find the mode, we need to look for the most repeated values in the set. Let's do it!
2.5 2.6 2.7 2.7
2.8 2.8 2.8 2.9
2.9 2.9 3.1 3.2
We can see that there are two values that are repeated three times. Therefore, the data has two modes: 2.8m and 2.9m. To find the range we will subtract the least value from the greatest value.
Range: 3.2 - 2.5 = 0.7
