Let x be Will's height, and y be Wanda's height.
Since Will is 23% taller than Wanda we have `x=1.23y`
(y+23% of y is 1y+.23y=y(1+.23)=1.23y)
Then solving for y we get:
`y=x/1.23=(100x)/(123)~~.813x`
So Wanda's height is approximately 81.3% of Will's height.