Case-control study for palak paneer with frozen spinach and e coli food poisoning Food poisoning (Cases) No food poisoning (Controls) Total Exposure Yes Ate palak paneer with frozen spinach A-168 B-370 538 Exposure No Did not eat palak paneer with frozen spinach C -72 D-133 305 Total 340 503 843 What is the exposure odds ratio for the association between food poisoning and NOT eating palak paneer