Personal collections
The weights of the green apples sold by a shop are normally distributed with mean 90 grams and standard deviation 8 grams. The shop also sells red apples. 
of the red apples sold by the shop weigh more than 80 grams. 160 red apples are chosen at random from the shop. Use a suitable approximation to find the probability that fewer than 105 of the chosen red apples weigh more than 80 grams.
