Answer:
x = [tex]\frac{4}{5}[/tex]
Step-by-step explanation:
given that y and x are proportional then the equation relating them is
y = kx ← k is the constant of proportionality
to find k use the given condition y = 15 when x = 3, hence
k = [tex]\frac{y}{x}[/tex] = [tex]\frac{15}{3}[/tex] = 5
y = 5x ← equation of proportionality
when y = 4, then
5x = 4 ( divide both sides by 5 )
x = [tex]\frac{4}{5}[/tex]
