Edexcel S2 2023 October — Question 1

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2023
SessionOctober
TopicBinomial Distribution
TypeAt least one success

  1. Sam is a telephone sales representative.
For each call to a customer
  • Sam either makes a sale or does not make a sale
  • sales are made independently
Past records show that, for each call to a customer, the probability that Sam makes a sale is 0.2
  1. Find the probability that Sam makes
    1. exactly 2 sales in 14 calls,
    2. more than 3 sales in 25 calls. Sam makes \(n\) calls each day.
  2. Find the minimum value of \(n\)
    1. so that the expected number of sales each day is at least 6
    2. so that the probability of at least 1 sale in a randomly selected day exceeds 0.95