$\backslash$table$[[,1,2,3,4,5,6,7,8,9,10,11,12],[$Month$,$Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec$],[$Sales$,51,55,54,57,50,68,66,59,67,69,75,73]]$

$7\mathrm{.}8\mathrm{.}1.$ Use a trend analysis to estimate the relationship between time and sales.

$7\mathrm{.}8\mathrm{.}2.$ Calculate the forecasts for the first four months of the new year.