Identify the distance between points (3,7,1) and (9,6,7), and identify the midpoint of the segment for which these are the endpoints. Round to the nearest tenth, if necessary.

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.