Hey kiddo, have you ever played with blocks? Imagine you have blocks of different colors and you want to find the middle block. Let's say you have 7 blocks, so you line them up in order from smallest to biggest, and then you count 3 blocks from the start and 3 blocks from the end. The block in the middle is called the median.
A median graph is similar to finding the middle block, but instead of blocks, we have lines with different lengths. These lines represent different quantities, like how many people live in different cities or how much money different families make. We want to find the "middle" quantity, so we line up the lines in order from smallest to biggest. Then we look for the line that splits the other lines into two equal groups - half of the lines are shorter than the median line, and half are longer. That line in the middle is the median line.
A median graph can be helpful to see the "average" or "typical" value in a set of data. It can also show us if there are any outliers, which are values that are much higher or lower than the majority of the other values. Just like the middle block in our tower of blocks, the median line in a median graph helps us understand the middle value in a set of data.