4 The time taken to cook an egg by people living in a certain town has a normal distribution with mean 4.2 minutes and standard deviation 0.6 minutes.
- Find the probability that a person chosen at random takes between 3.5 and 4.5 minutes to cook an egg.
\(12 \%\) of people take more than \(t\) minutes to cook an egg. - Find the value of \(t\).
- A random sample of \(n\) people is taken. Find the smallest possible value of \(n\) if the probability that none of these people takes more than \(t\) minutes to cook an egg is less than 0.003 .