Stat 257.01 Fall 2004
Assignment #2 (Selected) Solutions
(3.2) Since the forester wants to estimate the total number of trees on a tree farm, and since a
map of the farm is available, we can assume that the population consists of all trees grown at
this t
Stat 257.01 Fall 2004
Assignment #3 (Selected) Solutions
(3.30) Very briey:
(a) As noted in exercise 3.28, there were 9965 teenagers aged 1218 years old and living in
households who were randomly selected for this survey. Those teenagers were classied as
Stat 257.01 Fall 2004
Assignment #1 Solutions
(2.1) There are two denitions of statistics that are possible here. A statistic is simply a
number computed from data; for example, the sample mean or sample median. The subject
of statistics is that branch of
Stat 257.01 Fall 2004
Assignment #4 Solutions
(4.10) An estimate of the proportion of students on campus in favour of converting from the
semester system to the quarter system is simply the ratio of those sampled who are in favour to
the total number samp
Statistics 257Applied Survey Techniques
Fall 2004 (200430)
Final Exam Solutions
Instructor: Michael Kozdron
1.
As in Denition 4.1 on page 79, a simple random sample of size n from a population of
size N is a probability sample in which any sample of size
Stat 257.01 Fall 2004
Assignment #5 Solutions
(5.1) We begin by computing pi from the given data:
p1 =
4
0.286
14
p2 =
2
0.222
9
p3 =
8
0.381
21
p4 =
1
0.167.
6
We can now use equation (5.13) to determine pST as our estimator of p, the proportion of
d
Stat 257.01 Fall 2004
Assignment #10 (Selected) Solutions
(11.2) In this case, we see that the technique of interpenetrating subsamples was used. Let the
index i denote the ith interviewer, i = 1, . . . , 10. We easily calculate that
y1
y3
y5
y7
y9
= 4.8
Stat 257.01 Fall 2004
Assignment #8 Solutions
(6.25) As noted, each brand serves as a strata. In order to use consistent notation with the
text, we will write strata A for brand I and strata B for brand II. In order to estimate y we
perform both a separat
Stat 257.01 Fall 2004
Assignment #9 (Selected) Solutions
(8.2) We let saws in industry i denote the ith cluster, so that the cluster sizes mi , i = 1, . . . 20,
are given by the number of saws column, and yi are given by the total repair cost column. Henc
Stat 257.01 Fall 2004
Assignment #7 Solutions
(6.8) There was a misprint in this problem in earlier editions of the text. The earlier editions
had y = 169 while the corrected editions have y = 2.6. If you use y = 169, though, then the
problem does have a
Stat 257.01 Fall 2004
Assignment #6 (Selected) Solutions
(2.7) (a) The mean is a good summary number for typical calories per serving for these drinks.
As such, the standard deviation is a good summary number for the variation in the calories
per serving.