[. . . ] [. . . ] Calculate the percent change (a) and the dollar difference (b) between two yearly sales figures $1, 500 in 1989 and $1, 300 in 1988. Correct function Clear the calculator (except memory) Clear the memory Clear the grand total memory Clear error conditions Key the contents of the memory and grand total The display will not appear by pressing the matically turned off. Key after the power iSi auto@ Calculate the cost (a) and the gross profit {b] from a selling price of $9, 780 on the Calculate the selling price tel and gross profit (b) from a cost of'$a, 950 on the basis of a 25% profit on the cost. Calculate the cost (a) and the gross profit [b} from a selling price of $500 on the basis of a 35% profit on the selling price. [. . . ] [. . . ]