Edexcel S2 — Question 6

Exam BoardEdexcel
ModuleS2 (Statistics 2)
TopicPoisson Distribution
TypeSingle time period probability

6. A shoe shop sells on average 4 pairs of shoes per hour on a weekday morning.
  1. Suggest a suitable distribution for modelling the number of sales made per hour on a weekday morning and state the value of any parameters needed.
  2. Explain why this model might have to be modified for modelling the number of sales made per hour on a Saturday morning.
  3. Find the probability that on a weekday morning the shop sells
    1. more than 4 pairs in a one-hour period,
    2. no pairs in a half-hour period,
    3. more than 4 pairs during each hour from 9 am until noon. The area manager visits the shop on a weekday morning, the day after an advert appears in a local paper. In a one-hour period the shop sells 7 pairs of shoes, leading the manager to believe that the advert has increased the shop’s sales.
  4. Stating your hypotheses clearly, test at the \(5 \%\) level of significance whether or not there is evidence of an increase in sales following the appearance of the advert.
    (4 marks)