17. 137lbs
i do 3 sets of skull crushers: 1st set: 10 lbs[10 reps]; 2nd: 10lbs [10 reps]; 3rd: 20 [7 reps]
3 sets of one arm cable extension: 1st: 20 lbs [10reps]; 2nd: 22.5 lbs [8] 3rd[6/7]
then:
chest:
decline: 1st: 30 [10 reps]; 2nd: 35 [ 8]; 3rd: 35[6/7]
iso lateral bench press: 40 lbs[10]; 2nd: 45[8]; 3rd: 45/47.5 [7]
Do your bench pressing first ALWAYS. The majority of growth stimulation comes from the heavy compound movements such as the bench or a squat. In fact, at 137 lbs you could completely skip tricep-specific excercises and your triceps will growth and virtually the same ratewhether you did skull crushers or not.
Isolation excercises should always take a back seat to te compound movements.
And why are you doing decline bench first? or at all for that matter? Just do flat and incline presing. Both Dumbbells and barbell.