Test 2 calculator section #19. I guessed and got it right but how do you do it?

The key to figuring out the median in a question like this is remembering that the median is the middle number in a set of numbers, once that set is sorted (or the average of the two middle numbers in a set with an even number of numbers).

In this case, 600 students were surveyed in total (300 from each of two schools) so we need to figure out the middle number, which will be the average of the 300th and 301st value, although a quick look at the answer choices tells us we won’t have to worry about taking any averages.

Use the table to figure out where the middle value will fall. There were a total of 120 + 140 = 260 students surveyed who said they had 0 siblings. From there, another 80 + 110 = 190 students said they had 1 sibling.

260 was less than 300, but 260 + 190 = 450 is greater than 300, so we know that we hit the 300th and 301st value somewhere in the one-sibling crowd. Therefore, the median number of siblings is 1.