The maximum wind speed on any given day in Dublin is modelled as Normally distributed with mean 10 knots and standard deviation 2 knots.
(a) Explain potential deficiencies of using the Normal distribution to model wind speeds.
(b) In a 5 day working week what is the probability that at least 2 of the days have maximum wind speed of more than 9 knots, using the Normal distribution?
(c) In a 7 day week, what is the probability that the sample standard deviation is less than 2.5 knots, using the Normal distribution?
I have solved the a) and b) part of the questions however I am a bit confused for the c) part. If anyone can help me over how to solve this.