What Ratio Should My Workouts Be?

I started a low-carb diet last May. I've become more conscious about my caloric intake recently, and over the past 10 months or so, I've lost almost 70 pounds. I am content where I am at, but from a body fat %, I could lose a few more pounds. Right now, I am at 181 pounds (height is 5' 11.75"). In terms of BMI, I am OK, but ideally, I'd like to be closer to 20%. Anyways, I used one of those gizmos that supposedly say how much body fat you have, and it said I have 18.9%. I'd like to get my BF closer to 15%.

All this being said, what should work ratio be? Keep in mind - being realistic - I will only exercise every other day (which is the rate I've been doing). I've done almost all cardio to this point, but everything I've read says I should do more weights. What is a good ratio assuming I work out four days a week? 3 days of weights vs 1 day of cardio? (1 pull, 1 push, 1 legs and 1 cardio)? Or 2 cardio days and 2 weights days?