The water level in a lake has changed by -16.8 feet over the last 2.5 years. what is the average change in the water level each year?
a) -6.72
b) -0.672
c) 0.672
d) 6.72

Afootball quarterback has two more chances to throw a touchdown before his team is forced to punt the ball. he misses the receiver on the first throw 25% of the time. when his first throw is incomplete, he misses the receiver on the second throw 15% of the time. what is the probability of not throwing the ball to a receiver on either throw?