This preview shows page 1. Sign up to view the full content.
STAT 854/454 Sampling Theory and Practice
Assignment 2
Due: Wednesday, February 4, in class
Format: standard A4 size paper, singlesided, with a cover page
1. Let
N
= 7
,
800 be the number of public schools in Canada. We wish to estimate
p
=
M/N
,
where
M
is the number of schools that have Wireless Internet Access (WIA).
(a) Find the required sample size
n
such that the estimate is accurate within 2 percentage
points, 19 times out of 20 under SRSWOR, assuming prior information on
p
is not
available.
(b) Redo (a) assuming
p
= 5% for the purpose of sample size calculation.
(c) If we do inverse sampling with
m
= 10 under selection without replacement, what is
the expected number of schools we have to sample? Assume
p
= 5% for the purpose
of planning.
(d) Redo (c) assuming selection with replacement.
2. Consider a stratiﬁed population with
H
= 3,
N
1
= 500,
N
2
= 1000,
N
3
= 1500,
σ
2
1
= 100,
σ
2
2
= 200,
σ
2
3
= 225, and we do stratiﬁed simple random sampling.
(a) Let
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 11/23/2010 for the course STAT 454 taught by Professor Da during the Fall '09 term at Waterloo.
 Fall '09
 da

Click to edit the document details