In order to make a box plot, we need five (5) data.
1. Minimum Data
2. Quartile 1( Q1)
3. Median
4. Quartile 3 (Q3)
5. Maximum Data
Based on the given data, here are the 5 values:
1. Minimum - 70
2. Quartile 1 - 76.5
3. Median - 79.5
4. Quartile 3 - 81.5
5. Maximum - 90
Now that we have the 5 values, let's draw the box plot. Here are the steps:
1. Draw a number line. The number line can start from 70 (minimum) and ends with 90 (maximum). The number line can also be from 60 to 100. (Number line depends on you.)
For this solution, we will use 60 - 100 with a distance of 5 per interval. See the number line below.
2. Let's plot the five values using dots.
3. Draw a box from Q1 to Q3.
4. Draw a vertical line for the median.
See the final box plot below.