( ( ( Approximately 30 ) ( to ( ( 37.5 hours ) ( a week ) ) ) ) . )
(ROOT (NP (NP (QP (RB Approximately) (CD 30))) (PP (TO to) (NP (NP (CD 37.5) (NNS hours)) (NP (DT a) (NN week)))) (. .)))
Approximately 30 to 37.5 hours a week.
(ROOT (S (NP (DT The) (JJ fetal) (NN period)) (VP (VBZ lasts) (NP (NP (QP (RB approximately) (CD 30)) (NNS weeks)) (NP (NNS weeks)))) (. .)))