• Samples are proxies for the population of interest
  • Unfortunately, samples vary
  • Larger samples exhibition less variation
  • Statistics vs parameters
  • Distributions involved in statistical inference
  • Sampling distribution of mean IQ
  • Collecting more IQ samples
  • Sampling distribution of mean die roll
  • Sampling distribution of mean project duration
  • Create a sampling distribution
  • Central limit theorem
  • Implications of the central limit theorem
  • Standard error of the mean (SEM)
  • Impact of sample size on SEM
  • What is a confidence interval?
  • 95% confidence interval
  • Bigger samples give greater precision
  • Smaller confidence levels result in tighter intervals
  • How should we interpret the confidence interval?
  • Random sampling
  • Simple random sampling
  • Stratified sampling
  • Cluster sampling
  • What is bootstrapping?
  • Estimating median life expectancy