Exercise

# Sample size for comparing proportions

Here we will calculate the sample size needed for a trial comparing the proportions in two groups. We will also find the minimum detectable proportion for a treatment group given the sample size and power.

Instructions

**100 XP**

- Use the
`power.prop.test()`

to calculate the sample size needed for a trial with a recovery percentage of 40% and 60% in the placebo and active treatment groups, respectively, and 80% power. - If 150 patients can be enrolled per arm, find the minimum detectable recovery percentage in the treatment group.