I have a question about the 2019 Probability L2 question d(ii)
So based on the answer in question d(i), there is a 0.05% chance that two randomly selected plates made by Eddy would weigh over 520g. So in my answer I mentioned that his mean is probably higher than the companies.
But in terms of standard deviation, the marking schedule says that Eddy’s standard deviation is also higher than the company’s. I can see why because greater standard deviation means greater spread, therefore more chance of choosing plates that are of greater weight.
However, in my answer, I said that standard deviation could be lower because the fact that Eddy randomly chooses plates that both weighed over 520g shows that his data is somewhat consistent, which means less variation, therefore, a smaller standard deviation. Is this thinking correct?