Use seasonalized time series regression analysis to develop a forecast of next year$$s quarterly

sales revenues for the line of personal computer. $(20$ Marks$)$

Year Quarter Sales

$119\mathrm{.}4$

$127\mathrm{.}5$

$136\mathrm{.}0$

$1412\mathrm{.}0$

$216\mathrm{.}6$

$225\mathrm{.}4$

$236\mathrm{.}4$

$2412\mathrm{.}0$