  ### Home > MC1 > Chapter 2 > Lesson 2.2.2 > Problem2-68

2-68.

Chloe collected data about the number of pets her classmates have. Here is her data: $3,2,1,1,0,0,1,3,2,3,2,1,3,5,35,1,1,3,2,$ and $1$.

1. What is the mean (average) number of pets owned by her classmates? What is the median number of pets?

To find the mean, start by adding all the pieces of data together.

$3+2+1+1+0+0+1+3+2+3+2+1+3+5+35+1+1+3+2+1=70$

Now, divide the sum by the number of pieces of data (in this case, $20$).

$\frac{70}{20}\;=\;3\frac{1}{2}$

Next, place the data in numerical order and find the middle number. That will be the median. $0,0,1,1,1,1,1,1,1,2,2,2,2,3,3,3,3,3,5,35$

The mean is $3.5$ pets and the median is $2$ pets.

2. One piece of this data is an outlier (a number that is much higher or lower than the rest of the data). If we remove that number, how does the mean change? How does the median change?

For this problem, you will need to repeat the steps from part (a), but remove the outlying piece of data.
Remember that an outlier is a piece of data which is unusually higher or lower than the rest of the data.

3. Is removing the outlier important when we interpret the data? Explain your thinking.