I'm interested in finding out whether the flu shot really works. I have data from a survey on 100 people who were asked if they had the flu shot and whether or not they got the flu. Assuming a = .05, is the flu shot effective at reducing the likelihood that one will get the flu?

Here are the results from the survey;

Flu Shot No Flu Shot

Flu 20 20 40

No Flu 30 30 60

50 50

What would be my null and alternative hypotheses?

How would I compute my test statistic?

How would conclude or summarize my results?

I'm trying to figure out what scale of measurement I would use in computing 1.Type of religion. 2 .Weight in pounds , and 3.List of runners who finished a race, from first place to last place?