Question

A researcher is interested in conducting an observational study looking at the incidence of breast cancer in women 40-65 years of age followed for a period of 15 years. The researcher is interested in showing that the incidence of breast cancer has risen from 24% to 35% since the last surveillance data was published covering this population. If the researcher wants to be 95% confident with 90% power, how many participants should be enrolled?

option A: 172.5~173

option B: 167.5~168

option C: 142.2~142

Answer 1

Option B is correct.