Sharilyn likes to exercise. When she goes to the gym she lifts weights and then does her cardio workout. To monitor the cardio part of her workout, Sharilyn uses a heart rate monitor. The graph to the right shows Sharilyn’s heart rate while she was on the treadmill.  

1. Approximately how many times did Sharilyn’s heart beat during her $25$-minute workout?

   Hint (a):

   Approximate the area under the curve using a trapezoid.

2. What was Sharilyn’s approximate average heart rate during her $25$-minute workout?

   Hint (b):

   Divide your answer in part (a) by $25$ minutes.