Hi

I have a data set of roughly 50 companies - each were asked to state the 
percentage of their work that they would classify as 'green' in nature. 
I want to run a test to show that over the sample, this differs from 
50%, i.e. on average there is not an even balance between green and 
non-green work being done.


If this was a normally distributed variable, I'd run a standard 
one-sample t-test - however the distribution is fairly positively skewed 
(most companies seem to report between 10-30% - a few report higher), 
but with a small spike at 100%. Therefore at the very least trying a 
non-paramtric equivalent alongside a t-test seems appropriate - however 
going through the SPSS menus I can't find the non-parametric equivalent 
to the one-sample t-test. Any ideas/refernces - I'm sure I'm missing 
something obvious here!

Thanks in advance for any help

Chris