Modeling union membership the table gives the thousands of U.S. workers who were union members for selected years from 1930 to 2009.
(a) With t = 0 representing 1900, find a cubic function that models these data.
(b) Find the critical values for the model and classify them.
(c) How well does the relative maximum from the model agree with the data?
(d) Do you think that union membership will reach a minimum and then increase as the model predicts? Explain.