Postal Rates U.S postal rates have steadily increased since 1932. Using data depicted in the table for the years 1932-2013, the cost in cents to mail a single letter can be modelled using a
Year | Cost | Year | Cost |
1932 | 3 | 1988 | 25 |
1958 | 4 | 1991 | 29 |
1963 | 6 | 1995 | 32 |
1971 | 8 | 2001 | 34 |
1974 | 10 | 2002 | 37 |
1975 | 13 | 2006 | 39 |
1978 | 15 | 2007 | 41 |
1981 | 18 | 2008 | 42 |
1981 | 20 | 2009 | 44 |
1985 | 22 | 2012 | 45 |
2013 | 46 |
a. Find the predicted cost of mailing a letter in
b. Find the rate of change of the postage cost for the years
c. Using the regression feature on a graphing calculator, find a cubic function that models these data, letting
d. Discuss whether the quadratic or cubic function best describes the data. Do the answers from part b or from part c best describe the rate that postages was going up in the years
e. Explore other functions that could be used to model the data, using the various regression features on a graphing calculator, and discuss to what extent any of them are useful descriptions of the data.
f.
g.
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Calculus For The Life Sciences
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