Answer:
y = 7.5[tex]\sqrt{x}[/tex]
Step-by-step explanation:
given y is directly proportional to [tex]\sqrt{x}[/tex] then the equation relating them is
y = k[tex]\sqrt{x}[/tex] ← k is the constant of proportion
to find k use the condition y = 75 , x = 100 , then
75 = k[tex]\sqrt{100}[/tex] = 10k ( divide both sides by 10 )
7.5 = k
y = 7.5[tex]\sqrt{x}[/tex] ← equation of proportion