# The total outstanding consumer credit of a certain country (in billions of dollars) can be modeled by the function C(x) = 9.31x*

The total outstanding consumer credit of a certain country (in billions of dollars) can be modeled by the function C(x) = 9.31x* - 85 23x° +287 09x? - 309.47x + 2651.7, where x is the number of years since 2008. The graph of C(x) is shown to the right. Complete parts (a) through (c). Consumer credit outstanding C(x 80004 7000- 6000- 5000- 4000- 3000 2000- 1000- 0- 0 2 4 6 8 X Number of years since 2008 dC a) Find dx dC b) Interpret the meaning of dC dx Choose the correct answer below. O A. The instantaneous rate of change of consumer credit in the year 2008 OB. The average rate of change of consumer credit in the year (2008 + x). O C. The average rate of change of consumer credit during the x years after 2008 OD. The instantaneous rate of change of consumer credit in the year (2008+x). c) Using this model estimate how quickly outstanding consumer credit was rising in 2014 Outstanding consumer credit was rising by $billion per year in 2014. (Simplify your answer. Type an integer or a decimal.)