The following graph shows the approximate value of the United States Consumer Price Index (CPI) from December 2006 through July 2007. A ,, CPI Doc ammu- 2007 209 203 207 206 205 204 203 202 20] > I U l 2 3 4 5 6 7 Dec-()6 July()7 (D The approximating curve shown on the figure is given by I(t) = 0.04t3 + 0.4t2 + 0.1t + 202 (0 s t s 7), where t is time in months since the start of December 2006. (b) Was inflation slowing or speeding up in May 2007? O slowing down 0 speeding up (c) When was inflation speeding up? When was inflation slowing? Inflation was speeding up prior to one third of the way through (a) Jse the model 0 estimate the monthly inflation rate in May 2007 (t = 5). [Recall that the inflation rate is ---Select-- v Ht) 1(r) .] (Round your answer to three decimal places.) 2007 and slowing down after that