MATH 3339 TEST 1 REVIEW QUESTIONS AND ANSWERS (GRADED A)

MATH 3339 TEST 1 REVIEW
QUESTIONS AND ANSWERS
(GRADED A)
Chebyshev's Inequality - ANSWER-The percentage of the observations that lie
within k standard deviations of the mean is at least 1 - (1/k^2) when k > 1

binomial distribution - ANSWER-Fixed probability; given number of trials; only 2
possible outcomes

mean for binomial distribution - ANSWER-μ = np

standard deviation for binomial distribution - ANSWER-σ = √(np(1-p))

R command: For binomial distribution, n=50 and p=0.4, find P(X <= 5). - ANSWER-
pbinom(5, 50, .4)

R command: For binomial distribution, n=50 and p=0.4, find P(X = 5). - ANSWER-
dbinom(5, 50, .4)

hypergeometric distribution - ANSWER-from two types of items (A and B); select
some fixed number; count how many of A you get

R command: For hypergeometric distribution, m=20, n=15, and k=5, find P(X <= 1).
m = things counted
n = not counted
k = amount selected - ANSWER-phyper(1, 20, 15, 5)
phyper(x, m, n, k)

hypergeometric formula for P(X=x). - ANSWER-P(X=x) = C(m, x) *C(n, k-x) / C(m+n,
k)

R command: get LSRL equation - ANSWER-lm(y~x)

interpret coefficient of determination - ANSWER-##% of the variation in y is
explained by the LSRL and x

poisson distribution - ANSWER-Probability distribution for the number of arrivals
during each time period

R command: poisson distribution, mean=2.8, find P(X <=1). - ANSWER-ppois(1, 2.8)

percentile - ANSWER-A point on a ranking scale of 0 to 100. The 50th percentile is
the midpoint; half the people in the population being studied rank higher and half
rank lower.