Another Classroom

Anomaly? Let's look at another classroom:

same story

Age (Years)	Circumcised?	Age at Operation	If not circumcised, want to be circumcised later?
16	Yes	12
17	Yes	11
17	Yes	9
17	Yes	9
17	Yes	13
17	Yes	12
17	Yes	11
17	Yes	4
17	Yes	16
16	Yes	12
16	Yes	2
16	Yes	12
17	Yes	11
17	Yes	2
17	Yes	11
17	Yes	10
16	Yes	11
16	Yes	13
17	Yes	9
16	Yes	13
16	Yes	11
17	Yes	14