Analysing relationships using autosomal DNA

I (A) am 1095 cm's from a known cousin (M).

I (A) am 1224 cm's from an unknown person (S)

My cousin (M) is 1458 cm's from the unknown person (S).

I (A) am described as a Cousin to (S) (M) is described as a close relation to (S)

A is 73, M is 79 and S is 89.

What conclusion can be drawn?

• Hi, welcome to G&FH.SE! Your question could be improved because as it is written it is not clear. Please use standard terminology. Don't make your readers guess what you really meant. – Jan Murphy Sep 30 '19 at 17:44

I think that your starting point for this question should be to use The Shared cM Project 3.0 tool v4 which suggests these relationships for the shared cM value between each pair:

• A and M are 6 years apart in age and share 1,095cM suggesting that they are first cousins, assuming from their age difference that they belong to the same generation. There is a tiny chance that they are half siblings.
• A and S are 16 years apart in age and share 1,224cM suggesting that they are first cousins, if they belong to the same generation. There is a tiny chance that they are half siblings. If they may be from different generations then it is possible that S is a half aunt or half uncle to A.
• M and S are 10 years apart in age and share 1,458cM suggesting that they are half siblings, if they belong to the same generation. There is a small chance that they are first cousins. If they may be from different generations then it is possible that S is an aunt or uncle, or maybe a half aunt or half uncle to M.

If you know the relationship between A and M then you may be able to tighten up your hypothesis but my first one would be that M and S are half siblings, and A is a first cousin to both.

As commented by @JanMurphy it is important to realize that

we cannot determine relationships by the raw numbers alone. We must use information from paper-trail research or knowledge of real-life relationships

to flesh out and check any hypotheses we make from the raw numbers.