I need help figuring this out

[CAGDNA]

I need help figuring this out; Please

I have a direct Y-67 to my grandfather and his only grandson.
I have a Family Finder match with his grandaughter and grandson
Grandson and grandaughter are 1st cousins (grandfathers sons are dead- no DNA test)
We all three match a 4th cousin in Family Finder on Grandmother's tree

Female 45 segments shared 1118.46 Longest segment
Male 37 segments Shared 1505.91

Male Female
119.28 166.86
116.38 100.34
107.11 84.74
97.91 65.07
94.08 55.07
89.91 54.47
88.49 50.1
75.14 46.53
74.81 44.02
74.64 33.4
74.3 33.18
70 32.61
61.28 28.19
51.95 25.7
44.02 21.92
33.49 20.92
29.46 20.84
29.03 19.67
25.75 19.54
25.58 18.85
23.32 16.79
16.76 15.2
15.37 13.95
13.93 12.64
11.63 11.41
10.53 10.99
8.94 10.87
5.97 10.61
4.46 9.44
2.83 9.21
2.43 8.08
2.14 6.5
2.06 6.35
1.49 4.81
1.43 4.02
1505.9 3.9
3.11
3.06
2.95
2.95
2.57
2.15
2.14
1.48
1.24
1118.44

I'm trying to figure out with of the two
sons of my grandfather is my father or what else I
need to do to find. Maybe it's not possible.
I have a paper trail on the paternal grandfather and grandmother.

[Earl Davis]

Congrats on the results. Please wait for others to add in here.

The female looks like a potential 1st cousin with a little more DNA in common with you than average.

The male is in the range of a half sibling but with a little less shared DNA than average. Uncles and Aunts might also fall into this range with you.

See
http://www.isogg.org/wiki/Autosomal_DNA_statistics

The spreadsheets there also give some good examples of a range of shared amounts of DNA but I am not sure if those cover half sibling scenarios.