Exercise

Comparing randomization inference and t-inference

When technical conditions (see next chapter) hold, the inference from the randomization test and the t-distribution test should give equivalent conclusions. They will not provide the exact same answer because they are based on different methods. But they should give p-values and confidence intervals that are reasonably close.

Instructions

100 XP

Calculate the absolute value of the observed slope, obs_slope.
Add a column to perm_slope of the absolute value of the slope in each permuted replicate. The slope column is called stat.
In the call to summarize(), calculate the p-value as the proportion of absolute estimates of slope that are at least as extreme as the absolute observed estimate of slope.