Exercise

# Working with R-output (1)

The p-value given by the `lm`

output is a two-sided p-value by default. In the twin study, it might seem more reasonable to follow along the one-sided scientific hypothesis that the IQ scores of the twins are *positively* associated. Because the p-value is the probability of the observed data or more extreme, the two-sided test p-value is twice as big as the one-sided result. That is, to get a one-sided p-value from the two-sided output in R, divide the p-value by two.

The linear regression model of `Foster`

vs. `Biological`

, `model`

, is provided in the script.

Instructions

**100 XP**

- Get the Biological coefficient from the model.
- Tidy the model.
- Filter for the
`term`

`"Biological"`

.

- Add a column,
`one_sided_p_value`

, of the one-sided p-value.