A researcher wants to estimate average annual healthcare spending across two regions using stratified sampling with a fixed budget of $12,000. Data: Region A: N_A = 100,000, σ_A = $800, cost per interview = $30; Region B: N_B = 50,000, σ_B = $1,200, cost per interview = $40. Under budget-constrained optimal allocation, the allocation proportions follow: $n_h \propto \frac{N_h \sigma_h}{\sqrt{c_h}}$

Approximately how many interviews should be conducted in Region A and B respectively?