The Processor Speed, in Megahertz, of Intel Processors Could Be $$P ( t ) = \left\{ \begin{array} { l l } 75 t + 200 & \text { if } 0 \leq t \leq 4 \\600 t - 1,900 & \text { if } 4 < t \leq 9\end{array} \right.$$

Multiple Choice

The processor speed, in megahertz, of Intel processors could be approximated by the function of time t in years since the start of 1995. $$P ( t ) = \left\{ \begin{array} { l l } 75 t + 200 & \text { if } 0 \leq t \leq 4 \\600 t - 1,900 & \text { if } 4 < t \leq 9\end{array} \right.$$
Use the model to estimate when processor speeds first hit 3.2 gigahertz (1 gigahertz = 1,000 megahertz) .

A) $t = 8.2$
B) $t = 9.0$
C) $t = 6.5$
D) $t = 8.5$
E) $t = 8.8$