I think there is a mistake:

Entropy S = -([9/14 responses, 5/14 no responses])

= -9/14 log2 9/14 - 5/14 log2 5/14 = 0.947 bits

It shoudn't be 0.947 bits but 0.940 bits...

And i just know how to calculate it in open office..just type

=-9/14 log(9/14;2) - 5/14 log(5/14;2) = 0.940