Do the data come from the population?
Recall that the observed difference (i.e. the difference in proportions in the homes dataset, shown as the red vertical line) was around -0.0078, which seems to fall below the bulk of the density of shuffled differences. It is important to know, however, whether any of the randomly permuted differences were as extreme as the observed difference.
In this exercise, you'll re-create this dotplot as a density plot and count the number of permuted differences that were to the left of the observed difference.
Cet exercice fait partie du cours
Foundations of Inference in R
Instructions
The homeown_perm dataset is available in your workspace.
- Using
geom_density(), plot the permuted differences. - Add a vertical red line with
geom_vline()where the observed difference falls.diff_origis provided in your workspace and represents the original value of the difference statistic. - Count the number of permuted differences that were less than or equal to the observed difference.
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Plot permuted differences, diff_perm
ggplot(homeown_perm, aes(x = ___)) +
# Add a density layer
___() +
# Add a vline layer with intercept diff_orig
___(aes(xintercept = ___), color = "red")
# Compare permuted differences to observed difference
homeown_perm %>%
summarize(n_perm_le_obs = sum(___ <= ___))