Cavalier using a lance on foot (please check my math)

[Cav5150]

Would this be correct?
Assume a 15th level cavalier with a +1 lance and power attack:

1) Lance on Foot w/PA
1d8 + [(4 str) + (2 Str) + (1 enhancement) + (12 PA) ] = 1d8+19

2) Lance on Foot w/PA critical hit
3d8 + 3* [(4 str) + (2 Str) + (1 enhancement) + (12 PA) ] = 1d8+57

3) Lance on Foot PA w/ Challenge
1d8 [(4 str) + (2 Str) + (1 enhancement) + (12 PA) + (15 Challenge) ] = 1d8+35

4) Lance on Foot PA w/ Challenge Crit
3d8 + 3*[(4 str) + (2 Str) + (1 enhancement) + (12 PA) + (15 Challenge) ] = 3d8+102

[Cult of Vorg]

2): 3d8 not 1d8.
3): 4+2+1+12+15=34 not 35.
Probably just typos, otherwise looks right to me, other than challenge same as any 12-15 BAB char with 18 str +1weapon and power attack.