The prices of Orr, Inc. stock $($y$)$ over a period of $12$ days, the number of shares $($in $100$s$)$ of company's stocks sold $(x_1),$ and the volume of exchange $($in millions$)$ on the New York Stock Exchange $(x_2)$ are shown below.

$\backslash$table$[[$Day$,(y),(x1),(x2)$