5 On average, 1 in 2500 adults has a certain medical condition.
- Use a suitable approximation to find the probability that, in a random sample of 4000 people, more than 3 have this condition.
- In a random sample of \(n\) people, where \(n\) is large, the probability that none has the condition is less than 0.05 . Find the smallest possible value of \(n\).