In a classic study of peptic ulcer, blood types were determined for 1,655 ulcer patients. The accompanying table shows the data for these patients and for an independently chosen group of 10.000 healthy controls from the same city.

(a) The value of the chi-square statistic for this contingency table is χ2s = 49.0. Carry out the chi-square test at α = 0.01.
(b) Construct a table showing the percentage distributions of blood type for patients and for controls.
(c) Verify the value of χ2s given in part (a).

Transcribed Image Text:

Blood type Ulcer patients Controls 911 579 124 41 1,655 4.578 4,219 890 313 10,000 AB Total