gistfile1.py

# report will be something like:
#
#   {   test_name: 'signup button',
#       alternatives: ['Red', 'Green'],
#       results: [
#           {   attempted: 248,
#               completed: 12
#           },
#           {
#               attempted: 226,
#               completed: 18
#           }
#       ]
#   }

num_trials = sum(r['completed'] for r in report['results'])
avg = float(num_trials) / len(report['alternatives'])
diffs = [r['completed'] - avg for r in report['results'])
avgdiff = sum(diffs) / len(report['alternatives'])
significant = pow(avgdiff, 2) > trials

if significant:
    print 'wahoo!'
else:
    print ':-('