I started with total US population and tried to carve out the right age bracket, roughly 14 to 18, which is about 5 years out of an 80-year lifespan.
Break down the problem using a top-down approach: start with the US population, estimate the number of high school-aged individuals (roughly ages 14-18), and then adjust for enrollment rates. Alternatively, use a bottom-up approach by estimating the number of high schools and average students per school, then multiply. Clearly state your assumptions and round numbers for simplicity.
Pro tip: Show your work and narrate your calculations step-by-step, as interviewers value logical reasoning over the exact number. Also, sanity-check your final estimate against known benchmarks (e.g., ~15 million high school students in the US) to demonstrate awareness.
Confirm whether 'high school students' means students currently enrolled in grades 9-12, including public and private schools. Ask if they want the total number or just a specific segment.
Decide between top-down (population-based) or bottom-up (school-based) estimation. For this question, top-down is often simpler and more accurate.
Start with US population (~330 million). Estimate the number of high school-aged individuals (ages 14-18) by assuming even age distribution over 80 years, so about 4.1% of population, or ~13.5 million. Adjust for enrollment rate (~95%) to get ~12.8 million.
Consider private school students (~10% of total) and dropout rates. Alternatively, use bottom-up: number of high schools (~25,000) times average students per school (~600) gives ~15 million, then adjust.
Compare your estimate to known data (e.g., National Center for Education Statistics reports ~15 million). If your estimate is off, explain why and adjust assumptions.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.