The sales of a magazine vary randomly: in 70% of weeks they are classified as being ‘high’ while in 30% of weeks they are classified as ‘low’. (i) Write down prior probabilities of high and low sales...

The sales of a magazine vary randomly: in 70% of weeks they are classified as being ‘high’ while in 30% of weeks they are classified as ‘low’.

(i) Write down prior probabilities of high and low sales in the coming week .........

(ii) You are now given the sales figures for Monday and these show low sales. In the past:

In weeks when sales turned out to be high, Monday had low sales on only 20% of occasions; In weeks when sales turned out to be low, Monday had low sales on 60% of occasions. Revise your prior probabilities in the light of Monday’s sales figures.