The drug Ancrod, which is supposed to reduce the risk of intracranial hemorrhaging in stroke victims, was tested in a double-blind clinical trial in which 500 subjects who had strokes were randomly divided into two even groups. One group received Ancrod and the other got a placebo. We can assume this sample was randomly selected from our population of interest and the observations are independent. Twelve of those in the Ancrod group and 21 of those in the placebo group experienced an intracranial hemorrhage. Carry out the appropriate test for this analysis. What is the test statistic, rounded to 2 decimal places