Exercise

# Sample size effects on bootstrap CIs

In a previous multiple choice exercise, you realized that if you resampled the data with the wrong size (e.g. 300 or 3 instead of 30), the standard error (SE) of the sample proportions was off. With 300 resampled observations, the SE was too small. With 3 resampled observations, the SE was too large.

Here, you will use the *incorrect* standard error (based on the incorrect sample size) to create a confidence interval. The idea is that when the standard error is off, the interval is not particularly useful, nor is it correct.

Instructions

**100 XP**

- A function for calculating the bootstrapped t-confidence interval,
`calc_t_conf_int()`

, is shown is the script. Read the code and try to understand it. - Call
`calc_t_conf_int()`

on`one_poll_boot`

to calculate the correct t-confidence interval. - Do the same on
`one_poll_boot_300`

, to find an incorrect interval for the resamples of size 300. - Do the same on
`one_poll_boot_3`

, to find an incorrect interval for the resamples of size 3.