Parameters and confidence intervals

Foundations of Inference in R

Jo Hardin

Instructor

Research questions

 

Hypothesis test Confidence interval
Under which diet plan will participants lose more weight on average? How much should participants expect to lose on average?
Which of two car manufacturers are users more likely to recommend to their friends? What percent of users are likely to recommend Subaru to their friends?
Are education level and average income linearly related? For each additional year of education, what is the predicted average income?
Foundations of Inference in R

Parameter

  • A parameter is a numerical value from the population

  • Examples (continued):

    • The true average amount all dieters will lose on a particular program

    • The proportion of individuals in a population who recommend Subaru cars

    • The average income of all individuals in the population with a particular education level

Foundations of Inference in R

Confidence interval

  • Range of numbers that (hopefully) captures the true parameter
  • "95% confident that between 12% and 34% of the entire population recommends Subarus"
Foundations of Inference in R

Let's practice!

Foundations of Inference in R

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