##############################################################
## Data here are from a medical study. Patients are 
## split into 18 groups, with each group having different 
## size (n.group).Patients in eacgh group undergo a 
## treatment of type A or B for a given duration (1-9 weeks). 
## The number of patients in each group responding to 
## treatment (n.resp) is recorded as the outcome of the study.
## Interested to explore whether response depends on 
## duration and/or type of treatment.
##############################################################


group n.resp n.group duration type
1	3	35	1	A
2	1	30	2	A
3	8	35	3	A
4	13	40	4	A
5	27	40	5	A
6	24	35	6	A
7	29	35	7	A
8	35	40	8	A
9	36	40	9	A
10	1	40	1	B
11	3	40	2	B
12	5	35	3	B
13	6	30	4	B
14	20	45	5	B
15	23	40	6	B
16	31	40	7	B
17	29	35	8	B
18	36	40	9	B