Binomial

• Binomial distribution - a distribution used for discrete data, defined by B (n,p).
• Binomial conditions


  Fixed number of trials

  Independent events

  Two outcomes

  Same probability
• mean = n x p
• variance = np(1-p)
• How do we calculate exact probabilities?

  Binomial PD
• How do we find cumulative probabilities?

  Binomial CD
• Spotting the binomial distribution


  Very likely to be hidden in a question, main thing to look out for is the fixed number of trials.
• Exam tips for binomial


  • can be combined with other distributions
  • if asked if it is suitable/not, state all 4 condition in CONTEXT
• • means being different / not tells us about the probability (correct / not)
  • variance being different / not tells us if the events are independent / not