Precalculus (6th Edition) Blitzer

a. $(2005,2006)$, $(2007,2008)$, and $(2009,2011)$, b. $(2006,2007)$ and $(2008,2009)$, c. $4$ d. $5$ e. positive f. $3.20$ dollars, in $2011$ g. $1.80$ dollars, in $2009$
Based on the given graph, we have: a. increasing over years $(2005,2006)$, $(2007,2008)$, and $(2009,2011)$, b. decreasing over years $(2006,2007)$ and $(2008,2009)$, c. there are $4$ turning points d. the degree of the polynomial function should be $5$ e. the leading coefficient should be positive as the end behavior is $x\to\infty, y\to\infty$ f. the maximum is about $3.20$ dollars, which happens in 2011 g. the minimum is about $1.80$ dollars, which happens in 2009