OK since someone requested:
1.a.i. ii. b. First define your variables. The letters in the first part are a clue.
Let L be the weight of a large egg
Let S be the weight of a standard egg
Next, turn what they're asking into a mathematical formula. Just disect the question word by word and this shouldn't be hard. Probability indicates that obviously, you're finding a probability, so you'll need Pr(something). Next, since it's asking for the probability that a standard egg is greater than four-fifths of the weight of the large egg, using your variables, this reads as
, so combine the two to get
So working from there, you're actually allowed to move terms inside the Pr, so multiply both sides by 5 and transpose to get:
<---recognise the link between this question and the first one
Then using the values you worked out before, use the normal distribution to calculate it.