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5) A box contains 8 packets of salt avour crisps (S) and 4 of cheese avour (C). Sam selects a packet at random and gives it to her friend. Then she randomly chooses another and eats it. a) Draw a tree diagram to represent this information. {3) Find the probability that: b) The second packet selected is cheese flavour. [2) c) The second packet is cheese avour, given that she selects at least one cheese. [2) 6) The scores on a test (x) of a set of students is modelled as a normal distribution with x " M65, 10'). a) State the proportion of students who score between 55 and 75. {1) b) Sketch the distribution of X and show the information from part a on the diagram. {2) c} Find Pix > 55) (1) 7) The distribution of heights, (H) cm, of a large group of women is modelled as a normal distribution with H " N{162, 6'). A woman is chosen at random. Find: a) PiH > 170) (1) b) P(H m) =03 {1) b) Explain why the median mass is 84kg {1]