Week 7 – Inference for Regression

1 Textbook Reading – Part 1

Required Reading: Exploring Sampling Variability

Reading Guide – Due Monday by the beginning of class

Download the Word Document

2 Textbook Reading – Part 2

Required Reading: Confidence Intervals for the Slope

Reading Guide – Due Wednesday by the beginning of class (note the new time!)

Download the Word Document

3 Concept Quiz – Due Wednesday by the beginning of class (note the new time!)

1. Match each item to it’s respective analogy:

point estimate

confidence interval

fishing with a net

fishing with a spear

2. To create a 95% confidence interval using the percentile method, what percentiles of the bootstrap distribution do you need to calculate?

  • 0th
  • 2.5th
  • 5th
  • 90th
  • 95th
  • 97.5th

3. To create a 95% confidence interval using the standard error method, what standard error do you use?

  • the sample standard deviation
  • the bootstrap distribution standard deviation
  • a resample standard deviation
  • 1.96

4. We almost never know if our confidence interval captured the true population parameter.

  • True
  • False

5. What percentage of 99% confidence intervals do you expect to capture the true population parameter?

6. The word “confident” in a confidence interval interpretation corresponds to what aspect of the interval?

  • the accuracy of the original sample
  • the reliability of the procedure for constructing confidence intervals
  • the precision of the bootstrap samples

7. Which of the following are true?

  • Smaller sample sizes tend to produce narrower confidence intervals.
  • Smaller sample sizes tend to produce wider confidence intervals.
  • Lower confidence levels tend to produce wider confidence intervals.
  • Lower confidence levels tend to produce narrower confidence intervals.

8. In a regression table, what does the “std_error” value associated with the slope represent?

  • the standard deviation of the sample
  • the standard deviation of the bootstrap distribution
  • the estimated standard deviation of the sampling distribution
  • the standard error of the sample

9. In a regression table, how is the “std_error” value calculated?

  • a mathematical formula
  • the standard deviation of the sample
  • the standard deviation of the bootstrap distribution

10. What percentage confidence interval is output in a regression table?

  • 99%
  • 95%
  • 90%

4 R Tutorial – Due Wednesday by the beginning of class

Required Tutorial: Practice the infer Workflow