9709 P62 - Jun 2011 - Q2
3329
In Scotland, in November, on average 80% of days are cloudy. Assume that the weather on any one day is independent of the weather on other days.
(i) Use a normal approximation to find the probability of there being fewer than 25 cloudy days in Scotland in November (30 days).
(ii) Give a reason why the use of a normal approximation is justified.
