A newsagent stocks 12 copies of a magazine each week. He has regular orders for nine copies, and the number of additional copies sold varies from week to week. The newsagent uses previous sales data to estimate the probability, for each possible total number of copies sold, as follows. Number of copies Probability 9 10 11 12 0.20 0.35 0.30 0.15

(a) Calculate an estimate of the mean number of copies that he sells in a week.

(b) The newsagent buys the magazines at 85p each and sells them at 1.45 each. Any copies not sold are destroyed. (i) Find the profit on these magazines in a week when he sells 11 copies. (ii) Construct a probability distribution table for the newsagent's weekly profit from the sale of these magazines. Hence, or otherwise, calculate an estimate of his mean weekly profit. (NEAB)