Exercise

# t-statistic

Using the permuted datasets (recall, the randomization forces the null hypothesis to be true), investigate the distribution of the standardized slope statistics (the slope, which has been divided by the standard error). Note that the distribution of the standardized slope is well described by a t-distribution.

Instructions 1/2

**undefined XP**

- Filter
`twins_perm`

for rows where`term`

equals`"Biological_perm"`

. - Calculated the degrees of freedom of
`twins`

, as the number of its rows minus two.