From a survey a company has determined that 23% of its customers are classified as "advocates", 68% as "passives" and the remainder as "detractors".

Research suggests that during a year 15% of the advocates will be lost to a competitor, whilst the percentages for passives and detractors are 20% and 40% respectively.

Accountants have determined that the company loses $800 of revenue for every advocate it loses, and $500 per years for other customers.

2. [2 marks] What proportion of customers will be lost to a competitor during a year?
4. [2 marks] If a customer is lost to a competitor during a year, what is the probability they were a detractor. Show your working.
6. [3 marks] What is the average lost revenue per customer per year associated with customers leaving? (NB Remember to include customers who don't leave in your calculations.)