Question

A clinic administers two drugs to two groups of randomly assigned patients to cure the same disease: 70 patients received Drug / and 80 patients received Drug II. The following table gives the information about the numbers of patients cured and those not cured by each of these two drugs.

Drug	Cured	Not Cured
I	60	10
II	59	21

For a chi-square test of homogeneity for this contingency table, what are the expected frequencies for the first row, rounded to two decimal places?

Answer 1

Following table shows the row total and column total:

	Cured	Not Cured	Total
I	60	10	70
II	59	21	80
Total	119	31	150

Expected frequencies will be calculated as follows:

ith row total jth row total Eij grand total

Following table shows the expected frequencies:

	Cured	Not Cured	Total
I	55.53	14.47	70
II	63.47	16.53	80
Total	119	31	150

Answer: Expected frequencies of first row are 55.53 and 14.47.