MATH355, Fall 06
EXAM
1A Key
12/10/06
1. Of 35 microcomputers available in a supply room, 20 have circuit boards for a printer, 5 have circuit
boards for a modem, and 13 have neither board. Using P to
Homework #9 Solution
3.71 A warehouse contains ten printing machines, four of which are defective. A company randomly selects
ve of the machines for purchase. What is the probability that all ve of th
Homework Solution # 4
3.1 Among 10 applicants for an open position, 6 are women and 4 are men. Suppose that three applicants
are randomly selected. Find the probability distribution for X , the number
Homework Solution # 3
2.27 Cars coming into an intersection can turn left, turn right, or go straight. Two cars enter an intersection
in succession. Find the probability that at least one of the two t
Homework Solution # 2
2.11 An experiment observes two cars in successive as they move through the intersection of two streets.
(a) All outcomes: let S, R, and L indicate the cars go straight, turn rig
Homework Solutions
2.1.
There are 10 elements in P, 5 in M, and 13 in neither P nor M. Since there are 25
computers, computers with both boards, i.e. P M, must have (10+5+13) 25 = 3.
(a) PM = 3.
(b) (
MATH355, Fall 06
EXAM
4 Key
12/1/06
1. From a group consisting of 3 Republicans, 2 Democrats, and 3 Independents, a committee of three
persons is to be randomly selected. Let X denote the number of Re
MATH355, Fall 06
EXAM
3 Key
11/08/06
k x2 (1 x)
0
1. Suppose that a random variable X has a p.d.f. given by f (x) =
for 0 x 1 .
otherwise
(a) Find the value of k that makes this a p.d.f.
1
ans:
1
kx2
MATH355, Fall 06
EXAM
2B Key
12/09/06
1. Let Y denote a random variable that has a Poisson distribution with mean = 2.2. Find the following:
(a) P (Y = 4)
(b) P (Y 4)
ans: (a) P (Y = 4) =
e
2.2
(c) P