Brandon works at a small petting zoo with 8 animals. He was looking at some data showing the masses of the animals. Each animal had a different mass between 2 and 160 kg. The zoo then buys a horse that weighs 900 kg as their 9th animal.

Animal Weight (in kilograms)
chicken 2
duck 3
goose 5
barn cat 7
dog 27
goat 36
lamb 45
pig 160
horse 900

How does buying the horse affect the mean and median?
Choose 1 answer

A. Both the mean and median will increase, but the median will increase by more than the mean.
B. Both the mean and median will increase, but the mean will increase by more than the median.
C. Both the mean and median will decrease, but the median will decrease by more than the mean.
D. Both the mean and median will decrease, but the mean will decrease by more than the median.

OPtion B. Both the mean and median will increase, but the mean will increase by more than the median.

Explanation:

You should not need to do calculations to determine how buying the horse affects the mean and median.

Without the horse, there are 8 animals. When the data are ordered, the median is the average of the 4th and the 5th weights: (7 + 27)/2.

With the horse, there are 9 animals. The median will be the 5th weight: 27

Then, the median increases from (7 +27)/2 to 27.

What about the mean?

The horse's weight is well beyond the weight of the other 8 animals. The range increases from 160 - 2 = 158 to 900 - 2 = 898.

Then, when you calculate the mean inlcuding the weigth of the horse, there will be a high increase.

Thus, without further calculations, you can conclude that "B. Both the mean and median will increase, but the mean will increase by more than the median"