The variable z is directly proportional to x and inversely proportional to y. when x is 12 and y is 18 z has the value 2 what is the value of z when x = 19 and y = 22

Find the volume of the described solid.the solid lies between planes perpendicular to the x-axis at x = 0 and x=7. the cross sectionsperpendicular to the x-axis between these planes are squares whose bases run from the parabolay=-31x to the parabola y = 30/x.a) 441b) 147c) 864d) 882