The median number of pets Mrs. Wigen's students have at home is 4.
The dot plot shows that the median number of pets Mrs. Wigen's students have at home is 4. This means that half of the students have 4 pets or less, and the other half have 4 pets or more.
To find the median, we first need to order the data from least to greatest. We can see from the dot plot that the data is already ordered, so we can simply count up to the middle value. Since we have 20 students, the middle value is the 10th value. The 10th value is 4, so the median is 4.
Here is a table of the data, with the values ordered from least to greatest:
| Number of pets | Number of students |
| 1 | 3 |
| 2 | 4 |
| 3 | 2 |
| 4 | 5 |
| 5 | 2 |
| 6 | 1 |
| 7 | 1 |
| 8 | 1 |
| 9 | 1 |
| 12 | 1 |
The median is the middle value, which is 4.
Another way to find the median is to draw a horizontal line through the middle of the dot plot. The value where the line intersects the most dots is the median. In this case, the line intersects the most dots at 4, so the median is 4.