(b) A company is contemplating the introduction of a new product. The marketing office estimates that the sales volume is normally distributed approximately with a mean of 5,000 units and a standard deviation of 1,000 units.

(i) Calculate the probability that the sales volume will be within the interval 6,500 units to 7,000 units. [4 marks]

(ii) What is the sales volume that the company has 10% chance to achieve or underachieve? [3 marks]

(c) The number of typing errors per page in a company annual report follows the Poisson distribution with an average of 0.25 error per page.

(i) Find the probability that there are 2 or more typing errors on a randomly selected page of the report. [4 marks]

(ii) For 5 randomly selected pages of the report, what is the probability that there are 2 pages each with 2 or more typing errors? [3 marks]