Susan has grades of 84, 65, and 76 on three math tests. what grade must he obtain on the next test to have an average of exactly 80 for the four tests?

The ivring berlin learning center would like a possible net profit of $650,000 on its new resource manual it sells to schools. the fixed costs for producing the manual are $780,000 and the variable cost per package is $19.85. if the estimated unit sales are 1,250,000 units, what selling price unit should the ivring berlin learning center try?