Question 1104869
inverse variation formula is y = k/x.


let F = y and let d^2 = x and you get F = k/d^2


F = 18 when d = 10, therefore the equation becomes 18 = k/100.


solve for k to get k = 100*18 = 1800.


k is the constant of variation, so k will always remain at 1800 in this equation.


you want to find F when d = 15.


formula becomes F = 1800 / 15^2.


solve for F to get F = 8.