Find the volume of this prism 8 9 11

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

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?