AQA S2 2008 January — Question 2

Exam BoardAQA
ModuleS2 (Statistics 2)
Year2008
SessionJanuary
TopicPoisson Distribution
TypeTwo independent Poisson sums

2 A new information technology centre is advertising places on its one-week residential computer courses.
  1. The number of places, \(X\), booked each week on the publishing course may be modelled by a Poisson distribution with a mean of 9.0.
    1. State the standard deviation of \(X\).
    2. Calculate \(\mathrm { P } ( 6 < X < 12 )\).
  2. The number of places booked each week on the web design course may be modelled by a Poisson distribution with a mean of 2.5.
    1. Write down the distribution for \(T\), the total number of places booked each week on the publishing and web design courses.
    2. Hence calculate the probability that, during a given week, a total of fewer than 2 places are booked.
  3. The number of places booked on the database course during each of a random sample of 10 weeks is as follows: $$\begin{array} { l l l l l l l l l l } 14 & 15 & 8 & 16 & 18 & 4 & 10 & 12 & 15 & 8 \end{array}$$ By calculating appropriate numerical measures, state, with a reason, whether or not the Poisson distribution \(\mathrm { Po } ( 12.0 )\) could provide a suitable model for the number of places booked each week on the database course.