WGU C459 Statistics Exam Questions & Answers
The probability of any event is between one and o. What is the equation for this? – ✔✔For any
event A, 0 ≤ P(A) ≤ 1.
The sum of all possible probabilities is___? – ✔✔One, the equation is :P(S) = 1
What is the complement rule? or the probability that an event does not occur is 1 minus the
probability that it does occur. – ✔✔P(not A) = 1 – P(A)
In probability, “OR” means either one or the other or both. – ✔✔P(A or B) = P(event A occurs or
event B occurs or both occur)
Two events that cannot occur at the same time are called – ✔✔disjoint or mutually exclusive
The Addition Rule for Disjoint Events: – ✔✔If A and B are disjoint events, then P(A or B) =
P(A) + P(B).
P(A and B) = – ✔✔P(event A occurs and event B occurs)
The idea of disjoint events is – ✔✔is about whether or not it is possible for the events to occur at
the same time
The idea of independent events is about – ✔✔whether or not the events affect each other in the
sense that the occurrence of one event affects the probability of the occurrence of the other
If A and B Disjoint – ✔✔A and B can not be indepentdent
If A and B are two independent events (Multiplication Rule) – ✔✔P(A and B) = P(A) * P(B).
if A, B and C are three independent events, – ✔✔P(A and B and C) = P(A) * P(B) * P(C)
The Complement Rule, – ✔✔P(A) = 1 – P(not A),
P(L) = 1 – P(not L) = 1 – P(not O1 and not O2 and not O3 and not O4 and not O5 and not O6 and
not O7 and not O8 and not O9 and not O10). – ✔✔Applying the Multiplication rule:Now, using
the multiplication rule, = 1 – (.56 * .56 * .56 * .56 * .56 * .56 * .56 * .56 * .56 * .56) = 1 – .003 =
.997.
P(at least one person chosen has blood type O) – ✔✔P((O and O) or (O and not O) or (not O and
O)) = (.44 * .44) + (.44 * .56) + (.56 * .44) = .6864.
If A and B are disjoint events – – ✔✔P(A and B)= 0