1. You are called in to investigate an outbreak of diarrhea after a dinner party. At the dinner party there were two dishes served, rare roast beef and three-bean salad. There were 25 people at the party. Thirteen people ate the rare beef (12 did not), and 10 of them are complaining of diarrhea. Of those that did not eat the rare beef, two people report diarrhea. Furthermore, twenty people ate the three-bean salad (5 did not), and 7 of them are complaining of diarrhea. Of those that did not eat the three-bean salad, 5 report diarrhea. (40 points)

a.Basedon the information above, construct a 2 x 2 table for the exposure of rare beefand the outcome of diarrhea.

	Diarrhea	No Diarrhea	Total
Rare roast beef
No rare roast beef
Total

b.Calculateand interpret the appropriate measure of association for assessing therelationship between eating rare roast beef and getting diarrhea with its 95%confidence interval.

c.Nowconstruct a 2 x 2 table for the exposure of three-bean salad and the outcome ofdiarrhea.

	Diarrhea	No Diarrhea	Total
Three-bean salad
No three-bean salad
Total

d.Calculateand interpret the appropriate measure of association for assessing therelationship between eating three-bean salad and getting diarrhea with its 95%confidence interval.

e.Whatis your preliminary conclusion about the cause of diarrhea at the picnic?

f.Isthe cause you selected necessary? Sufficient?Both? Neither? Please justify youranswer based on the evidence given.