Lab 06: Two Sample t-test

Use the dataset penguins. Download the data and save the CSV file into your Lab06 directory (so that it is submit when you upload your Lab06 folder). Load the dataset into R.

Read the help file about penguins, to better understand the data set.

Please submit a folder containing your Quarto input (qmd) and output (html) documents for this lab, named Lab06, to our shared Google Drive folder when you are finished.

Compare penguins across the categorical variable sex for a numerical variable of your choice.

  1. Make a box plot of your numerical variable across the levels of the variable sex.

  2. State one interesting thing about your plot in context of the data.

  3. Make a 90% confidence interval for the difference in means.

  4. Interpret your confidence interval in context of the data.

  5. State more clearly what your confidence interval suggests about the mean difference between penguin sexes. Where are these penguins from? Do these conclusions hold for all penguins everywhere?

  6. Perform a hypothesis test of these data, using a level of significance that appropriately matches your confidence interval above. Please state your hypotheses.

  7. Based on your test, which hypothesis is more likely given the data? State your conclusion as either “reject H0” or “fail to reject H0”, and explain why this conclusion is appropriate.

  8. Interpret in context of the data your conclusion of the hypothesis test.

  9. State more clearly what your hypothesis test suggests about the data.