Question

HELLLPPPPPPP .... The probabilities of a test are represented by I for infected; U, uninfected; D, infection detected; and N, no infection detected. What is the symbolic way to represent the probability of a true positive?

A.
`"P"("I" nnn "D")`

B.
`("P"("I" nnn "D"))/("P"("D"))`

C.
`("P"("U" nnn "N"))/("P"("N"))`

D.
`"P"("I" uuu "D")`

Answer 1

A) P ( I ∩ D )

Explanation:

To find a true positive, we need to find the chance of two events happening: an infection is detected and the person has said infection. That means that it is when both I and D are true.

When in a set, two events happen simultaneously, it is shown with a ∩ (intersection) symbol.

That means that a true positive is shown as P (I ∩ D)

Answer 2

P(I⋂D)

Explanation:

The symbolic way to represent the probability of a true positive is P(I⋂D).

We know that I stands for Infected, U stands for Uninfected, D for Infection detected, N for infection no detected.

Then, a true positive will be given by the intersection of Infected and Infection Detected.