Answer:
A = 4
Step-by-step explanation:
Given that F is directly proportional to A then the equation relating them is
F = kA ← k is the constant of proportion
To find k use the condition F = 36 when A = 9, then
36 = 9k ( divide both sides by 9 )
4 = k
F = 4A ← equation of proportion
When F = 16, then
16 = 4A ( divide both sides by 4 )
4 = A
