Answer:
The equation of the relation ⇒ 
y = 18
Step-by-step explanation:
∵ y ∝ x/z
∴ y = kx/z
∵ y = 18 , x = 15 and z = 5
∴ 18 = 15k/5 ⇒ 18 = 3k
∴ k = 18/3 = 6
∴ y = 6x/z
∵ x = 21 and z = 7
∴ y = (6 × 21)/7 = 18
Answer:
HK = 24
Step-by-step explanation:
HK and JL are diagonals of the parallelogram.
Recall that diagonals of a parallelogram bisect each other. This implies that, they divide each other into equal parts.
Therefore,
HK = 2(HM)
HM = 12
Thus,
HK = 2(12)
HK = 24
Answer: Tammy's sample may not be vaild because she surveyed the students only from her class and it is likely that other classes might not like the subject maths. She might get the accurate results by surveying a larger number of people in the school instead of just her class.