Following Are Some Approximate Values of the Amex Gold BUGS $$\begin{array} { | l | l | l | l | } \hline \text { Year } & 1995 & 2000 & 2004 \\\hline \text { Index } & 200 & 50 & 250 \\\hline\end{array}$$

Following are some approximate values of the Amex Gold BUGS Index. $$\begin{array} { | l | l | l | l | } \hline \text { Year } & 1995 & 2000 & 2004 \\\hline \text { Index } & 200 & 50 & 250 \\\hline\end{array}$$ ​
Take t to be the year since 1995 and y to be the BUGS index.
(a) Model the 1995 and 2000 data with a linear equation.
y = __________
(b) Model the 2000 and 2004 data with a linear equation.
y = __________
(c) Use the results of parts (a) and (b) to obtain a piecewise linear model of the gold BUGS index for 1995-2004. $y = \left\{ \begin{array} { l l } \_\_\_\_& \text { if } 0 \leq t \leq\_\_ \\\_\_\_\_& \text { if } \_\_< \mathrm { t } \leq 9\end{array} \right.$
(d) Use your model to estimate the index in 1999.
y = __________