Question 1022740
{{{y = k/x^2}}} for some constant of proportionality.  If x is halved...

{{{y = k/(x/2)^2 = (4k)/x^2}}}, making the new y value four times as big as the old y value.

If x was tripled, then 
{{{y = k/(3x)^2 = k/(9x^2)}}}, making the new y value nine times as small as the old y value.