John exercised 20% more than Toby. So the number of hours that John exercises per week is 14 + 0.2(14) = 14 + 2.8 = 16.8.
Jenny exercises two more hours than John. So the number of hours that Jenny exercises per week is 16.8 + 2 = 18.8.
So an expression representing the number of hours that Jenny exercises after w weeks is 18.8w.
The five-number summary is the minimum, first quartile, median, third quartile, and maximum. In a box plot, we draw a box from the first quartile to the third quartile.