In a classic study of peptic ulcer blood bypes were determin

In a classic study of peptic ulcer, blood bypes were determined for 1,655 ulcer patients. The lniuitab output below shows the data for these patients and for an independently chosen group of 10.000 healthy controls from the same city. Note that several entries in the output have been hidden by *\'s. Compute the missing entry *E*, **F**, and DF in the output. Carefully state the null and alternative hypotheses HO and HA. Give your decision about the test result at the significance level of 0.01. Give your conclusion in the context of research.

Solution

df = (r-1)(c-1)

= 3

------------------------------

E=681.31

F= chi square value for the particular cell = (o-e)^2/e =15.36

b) H0: Counts expected for all blood groups are equal

Ha: atleast two differ

The p-value is < 0.00001. The result is significant at p < .01.

Reject null hypothesis.

All blood groups do not have the same expected counts and this is statistically evidence at 1% significance.