Exercise

# Parameter estimates of beak depths

Estimate the *difference* of the mean beak depth of the *G. scandens* samples from 1975 and 2012 and report a 95% confidence interval.

Since in this exercise you will use the `draw_bs_reps()`

function you wrote in chapter 2, it may be helpful to refer back to it.

Instructions

**100 XP**

- Compute the difference of the sample means.
- Take 10,000 bootstrap replicates of the mean for the 1975 beak depths using your
`draw_bs_reps()`

function. Also get 10,000 bootstrap replicates of the mean for the 2012 beak depths. - Subtract the 1975 replicates from the 2012 replicates to get bootstrap replicates of the difference of means.
- Use the replicates to compute the 95% confidence interval.
- Hit 'Submit Answer' to view the results!