The median is the middle value in a set of data when the data is arranged in ascending order. If the data set has an odd number of observations, the median is the middle number.

If the data set has an even number of observations, the median is the average of the two middle numbers.

From the table, we have the following data set: 8 (2 times), 10 (1 time), 12 (4 times), 16 (3 times), 18 (3 times), 20 (1 time), 24 (6 times).

When arranged in ascending order, the data set looks like this: 8, 8, 10, 12, 12, 12, 12, 16, 16, 16, 18, 18, 18, 20, 24, 24, 24, 24, 24, 24.

This data set has 20 observations, which is an even number. Therefore, the median is the average of the 10th and 11th numbers in the sorted data set. The 10th and 11th numbers are both 16, so the median is 16.