Edexcel S2 2019 January — Question 2

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2019
SessionJanuary
TopicPoisson Distribution
TypeFinding minimum n for P(X≥k) threshold

  1. During morning hours, employees arrive randomly at an office drinks dispenser at a rate of 2 every 10 minutes.
The number of employees arriving at the drinks dispenser is assumed to follow a Poisson distribution.
  1. Find the probability that fewer than 5 employees arrive at the drinks dispenser during a 10-minute period one morning. During a 30 -minute period one morning, the probability that \(n\) employees arrive at the drinks dispenser is the same as the probability that \(n + 1\) employees arrive at the drinks dispenser.
  2. Find the value of \(n\) During a 45-minute period one morning, the probability that between \(c\) and 12, inclusive, employees arrive at the drinks dispenser is 0.8546
  3. Find the value of \(C\)
  4. Find the probability that exactly 2 employees arrive at the drinks dispenser in exactly 4 of the 6 non-overlapping 10-minute intervals between 10 am and 11am one morning.