Question 1:

The weights of population of apples are normally distributed with mean mg and standard deviation mg. It is

known that 25 % of the apples are heavier than 172 mg and 10 % are lighter than 150 mg

a) Illustrate a diagram to show the distribution of weights based on the given information and show that

= 150 + 1.2801.

b) Write down the 2nd equation based on given information and find the value of and value of ()

c) An apple is selected random from the population. Find the probability that it is heavier than 165 mg

d) Find the value of weight above which 60% of the apples lie.