Sorry, but this is too difficult. I need to work on my calculator, but I am not confident how:
The weights, in kg, of men in a random sample from a given population can be modelled by a normal distribution with mean 83.5 and 16.8.
a) What is the value above which 20% of the weights of men from the population will lie?
b) What is the range of values, symmetric about the mean, within which approx 95% of the weights of men will lie?
c) What is the percentage of weights of men above 100 kg.