PSTAT Test UPDATED Exam Questions and CORRECT Answers

PSTAT Test UPDATED Exam Questions
and CORRECT Answers
P(A and B) - CORRECT ANSWER - P(A)xP(B)
P(A)xP(B|A)


P(A or B) - CORRECT ANSWER - P(A)+P(B)-P(A and B)



P(A|B) - CORRECT ANSWER - P(A and B)/P(B)



mean - CORRECT ANSWER - u=Σxp



variance - CORRECT ANSWER - o²=(Σx²p)-u²



standard deviation - CORRECT ANSWER - o=√o²



factorial - CORRECT ANSWER - n!=n(n-1)(n-2)(n-3)...



combination - CORRECT ANSWER - nCx=(n!)/(n-x)!x!



Binomial probability criteria - CORRECT ANSWER - 1. there is a fixed number of trials
2. these n trials are independent
3. the outcome of each trial can be designated as a success or a failure
4. for each trial, the probability of a success if the same and is denoted by p.


Binomial probabilities - CORRECT ANSWER - p(X=x)= nCx(p^x)(1-p)^n-x

, Binomial distribution - CORRECT ANSWER - bin (n, p)


n: # of trials
p: probability of success


mean of binomial random variable - CORRECT ANSWER - µ=np



standard deviation of binomial random variable - CORRECT ANSWER - σ=√np(1-p)



P(A' and B') - CORRECT ANSWER - 1-p(A or B)



P(A'|B) - CORRECT ANSWER - 1-P(A|B)



P(A' or B') - CORRECT ANSWER - 1-P(A and B)



P(A and B') - CORRECT ANSWER - P(A)-P(A and B)



uniform distribution - CORRECT ANSWER - X ~ U(a,b)
all solutions are equally likely


mean of uniform distribution - CORRECT ANSWER - µ= (a+b)/2



normal distribution - CORRECT ANSWER - X ~ N (µ,σ)
follows the normal curve


z - CORRECT ANSWER - z=(x-µ)/σ