W- (3,4)
Z- (-1,1)
X-(-1,-3)
Y-(-4,1)
Answer:

Step-by-step explanation:
We are given that

Side of base=4 cm
l=w=4 cm
Height,h=12 cm
We have to find the rate at which the water level rising when the water level is 4 cm.
Volume of pyramid=


Substitute the value

Differentiate w.r.t t

Substitute the values


F(x) = x/4
so
f(-8) = -8/4 = -2
answer
f(-8) = -2
The surveyor selects the twentieth student who enters the building. The student do not enter the building to be surveyed but for other reasons and the researcher take advantage of that and selects them. This is a form of continence sampling.
The researcher selects every twentieth student and not any other. Therefore, the sampling is systematic in nature.
Finally, students selected to participate in the survey are free to choose if to participate in he survey or not. Therefore, it is voluntary kind of sampling.
Therefore, the applicable sampling methods are convenience, systematic, and voluntary.