Examine whether the proportions are correct by cross multiplying.

a) [[$ \displaystyle\frac {3} {2} = \displaystyle\frac {9} {6} $]]



The proportion is correct incorrect.

b) [[$ \displaystyle\frac {4} {5} = \displaystyle\frac {5} {6} $]]



The proportion is correct incorrect.

c) [[$ \displaystyle\frac {1} {4} = \displaystyle\frac {3} {12} $]]



The proportion is correct incorrect.

d) [[$ \displaystyle\frac {2} {9} = \displaystyle\frac {3} {11} $]]



The proportion is correct incorrect.