I know there is some disagreements on groups and size or measurements of groups.Not that it should make that much difference. I actually think a lot of this has to do with how people measure them and by what means.
First off this is not a "shot" group. This was made with the wonders of Paint Shop. But for kicks, I will have you measure that group and tell me how you read it.
Each square is 1" by 1" so that should make things a little easier for you. We are not interesting in exact measurement with a caliper, just your educated guess and then maybe explain to the group how you do measure the spread of a group...