If the endpoints of have the coordinates a(9, 8) and b(-1, -2), what is the midpoint of ab?
a.
(5, 3)
b.
(4, 5)
c.
(5, 5)
d.
(4, 3)

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.