Major issues with this study:

Key Aspects of Education Costs in NigeriaPrimary & Junior Secondary:

Officially free in public schools, but hidden fees (development levies, PTA) are common.

Federal Technical Colleges: These are tuition-free, with the government covering costs for uniforms and books.

Senior Secondary & Tertiary: Not generally free. State-owned schools, while cheaper than private, still charge fees, and federal universities charge significant "acceptance" or facility fees.

Regional Differences: Free education initiatives can vary significantly by state.

In other words how long the girl stays in school is directly correlated to how much money the family has.