HW1
Chapter 1
1.1
Method (c) is probably best, with (e) being the second best. Method (a) will generate a sample of college
age, method (b) will probably generate a sample of certain social-economic class. Method (d) is a
voluntary sample where sample mem
STAT 35000
Solution to Homework 5
Chapter 5
5.1. cfw_4 choose 2 (3/5)2(2/5)2 + cfw_4 choose 3 (3/5)3(2/5) + cfw_4 choose 4 (3/5)4 =
513/625 = .8208
5.4. cfw_4 choose 3 (3/4)3(1/4) = 27/64 = .4219.
5.11. If X denotes the number of lotteries you will win, t
An environmentalist collects a liter of water from each of 45 different locations along the banks
of a stream. He measures the amount of dissolved oxygen in each specimen. The mean oxygen
level in the sample is 4.62 mg. Assume the population standard devi
STAT 35000
Solution to Homework 6
Chapter 6
6.1. Let A denote the sample average. (a) If n=2, then P(A=0)=.04, P(A=0.5)=.12,
P(A=1)=.09, P(A=1.5)=.20, P(A=2)=.30, P(A=3)=.25; E[A]=E[X]=1.8,
Var(A)=Var(X)/2=0.78.
(b) If n=3, then P(A=0)=.008, P(A=1/3)=.036
To assess the accuracy of a thermostat, a controlled environment is known to have a temperature of 20 oC .
The temperature reading on the thermometer is repeatedly recorded a total of n times and the sample
mean is computed. Suppose the thermostat reading
HW2
Chapter 3
3.8
S
E
F
1
2
3
Figure 1
S
F
Figure 2
E
1
2
3
4
S
E
2
1
5
G
F
3
6
4
7
8
Figure 3
(a) See figure 1: EF = part 2, which is contained in E. EUF = parts 1, 2, 3, which contains E
(b) See figure 2: Fc = part 3, Ec = parts 2, 3. So, Ec contains Fc
A barber shop averages 6.5 customers per hour between 12:00pm and 5:00pm. Let X be the number of
customers arriving between 2:00pm and 3:30pm.
1. What is the distribution of X? That is, write down the name of the distribution and also give the
parameter v