A test was conducted on the staff at my workplace to identify each persons lung capacity. The data we got from the tester was whether or not each person "passed" or "failed". Lets say 50 people were tested and 30 passed.
I now want to split the workers into two groups "factory workers" and "Office workers" and see if there is a difference between their results. Would my null hypothesis be that factory workers and office workers have the same lung capability?.
What test for significance should I use? Would my population mean be 60% (30/50)?