MathCastle
StatisticsSuperchallengeBinomial and Geometric

Binomial and Geometric · Superchallenge problem

A plane has 200200 seats and each ticket holder shows up with probability 0.90.9, independently. The airline sells nn tickets and wants P(more than 200 show up)≤0.05P(\text{more than } 200 \text{ show up}) \le 0.05. Using the normal approximation with continuity correction and z=1.645z = 1.645, what is the largest nn it can sell?