Median = 75 because that is where the middle line of the box is.
First quartile = 70 because that is what the left edge of the box represents.
Third quartile = 85 because the right edge of the box indicates that.
Maximum = 100 because at the far right is the maximum data point of your data set.
The middle 50% of that data is between 70 and 85 because those are the values the box covers. It goes from the first quartile, 70, and stretches all the way to the third quartile 85.
