Answer:
y = 1.8
Step-by-step explanation:
given y is in direct proportion to x then the equation relating them is
y = kx ← k is the constant of proportion
to find k use the condition x = 25, y = 5 , then
5 = 25k ( divide both sides by 25 )
[tex]\frac{5}{25}[/tex] = [tex]\frac{1}{5}[/tex] = 0.2 = k
y = 0.2x ← equation of proportion
when x = 9 , then
y = 0.2 × 9 = 1.8
