Grade 6,7, and 8 at a middle school each have 180 students. the student council is throwing a school dance and they want to know what theme to have for the dance. since the student council cannot ask everyone they will survey a group of students. which sample can best the council to draw conclusions about the preferences of all the students in the school.
a. 6 students from each grade
b. 25 students from each grade
c. 6 students from the entire school
d. 25 students from the entire school

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of florida was approximately two times the population of california. b. the population of florida was approximately twenty times the population of california. c. the population of california was approximately twenty times the population of florida. d. the population of california was approximately two times the population of florida.

Someone answer asap for ! michele pushes a box d meters across a floor. she uses a force f, in newtons, to push the box. she pushes the box for t seconds. the formula p = fd/t calculates the power, p, in watts, that it takes for michele to complete the task. solve the formula for d.