anlower. 2. A manager wishes to estimate the likely impact on salary costs due to promotion of workers in his division. There are 8 members of staff who have applied for promotion, and he estimates that the average probability of success is 0.3. Any staff member who receives a promotion will cost the company an additional $3500 per annum. (a) What distribution do you think would be most suitable for modelling the number of staff promotions? Give reasons for your answer. (b) What is the expected additional salary cost due to promotions? What is the probability that fewer than 2 staff are promoted? What assumptions have you made in answering (c)? Are they likely to be justified here? Optional Extra