Analyzing interest rates: The graph shown approximates the average annual interest rates I...

Analyzing interest rates: The graph shown approximates the average annual interest rates I on 30-yr fixed mortgages, rounded to the nearest %. Use the graph to estimate the following (write all answers in interval notation).

a. domain and range

b. interval(s) where I(t) is increasing, decreasing, or constant

c. location of any global maximum or minimum values

d. the one-year period with the greatest rate of increase and the one-year period with the greatest rate of decrease

Source: 2009 Statistical Abstract of the United States, Table 1157