PleSw do question 11 and 12

Question 9 - 10 (1 mark each = 2 marks) The number of air-conditioning units sold during a week in a particular store in the Parramatta CB is given below, along with its probability distribution. X 0 2 3 4 P(X) 0.1 0.3 0.3 0.2 0.1 9. What is the expected value for the number of air-conditioning units sold in a week? A 2.0 B 1.9 C 2.1 D 1.5 10. What is probability that the store sells at least three air-conditioning units in a week? A 0.7 B 0.1 C 0.3 D 0.2 Question 11 - 12 (1 mark each = 2 marks) The records of a fancy shoe store show that 60% of customers making a purchase pay by credit card Suppose 10 customers purchased shoes from the store yesterday morning. 11. What is the probability that at most three customers paid by credit card? A 0.055 B 0.012 C 0.988 D 0.945 12. What is the expected number of A 6 B 4 purchases made by credit card? C 60 D 8 Question 13 - 15 (1 mark each = 3 marks) Focus