throughput accounting ratio

I have questions related to throughput accounting ratio.

1) Return per factory hour is calculated by considering the throughput return (sales – material cost) divided by the labour hour per unit.

2) Cost per factory hour is calculated by considering the total factory costs (all costs except material cost) divided by the total limited labour hours available.

3) Throughput accounting ratio is calculated by considering return per factory hour divided by the cost per factory hour which tells us the return per hour as compared to all fixed costs in the percentage figure to see whether the return from the a product is more than its fixed cost incurred or not.

All Correct?