Which metric reports on how often a channel contributes to a conversion prior to last-click attribution?

What report shows the percent of site traffic that visited previously?

Referrals report Frequency & Recency report New vs Returning report Sales Performance report Download Google Analytics Individual Certification Exam Answers (PDF)

What model represents the hierarchical structure of a Google Analytics account?

Account > View > Property Property > Account > View Account > Property > View View > Account > Property Download Google Analytics Individual Certification Exam Answers (PDF)

What metric-dimension combination is not valid?

Sessions / Source Total Events / User Type Time on Page / Device Category Sessions / Bounce rate Download Google Analytics Individual Certification Exam Answers (PDF)