Hi! This is for Epidemiology but CourseHero doesn't list the subject.

I'm having trouble with this question. There are 2 parts. I have the answer for them but I'm having a hard time understanding the concept. Could you please explain how prevalence works? Thank you!

A study published inArchives of Internal Medicine(Trump, Hyams, Cross and Struewing, 1993) determined the current prevalence of tuberculin reactors among young adults entering the U.S. Navy. 2,214 male recruits were tested in January and February 1990; 55 tuberculin reactions.

Part I:

What was the overall prevalence of tuberculin reactors in the male Navy recruit population?

Enter your numeric answer into the field below; do not round your answer.

My answer: .0248 --> I divided 55 rxns/2214 male recruits

Part II:

Now, calculate theexpected number of prevalenttuberculin reactors in the male Navy recruit population per 100 recruits.

Enter your numeric answer into the field below.

My answer: 2.4842 --> I multiplied .0248 by 100