Transcript QM-Chapters 1-4 exercises

QM
Winter 2009
Exercises for Test 1
Chapter s 1- 4 Del Balso
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Probability Sample
Any sample that is chosen by chance. Includes
Simple Random Sample (SRS) and Stratified
Samples.
1. Simple Random Sample
Gives each individual in the population an equal
chance of being chosen.
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Use table of random digits (handout) or computer
program to choose individuals or samples.
Random: every individual or sample has an equal
chance of being picked.
This ensures the sample is representative of the
population.
Therefore, we can generalize the results back to the
population.
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Choose a Simple Random Sample (SRS)
Step 1. Assign a number to every individual in the
population (or to every sample).
Assign numbers beginning with 0 and keep going until
everyone has a number. Go down columns of lists.
Step 2. Use random digits to select the numbers and
choose those people.
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The first two lines of the Random Digit Table p 550:
Line
101
102
19223
95034
05756
28713
96409
12531
42544
82853
73676
47150
99400
01927
27754
42648
82425
36290
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Ex., Choose a Simple Random Sample of 4 from the
following past players of the Canadiens. (number
down beginning with 0). Begin at line 101.
Ribeiro
Brisebois
Markov
Souray
Sundstrom
Hainsey
Ryder
Rivet
Hossa
Zednik
Dackell
Gratton
Koivu
Bouillon
Langdon
Perreault
Kilger
Theodore
Bulis
Quintal
Dwyer
Dagenais
Ward
Higgins
Juneau
Begin
Plekanec
Garon
Komisarek
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The sample of 4 is: Komisarek (19); Hossa (22);
Perreault (05); Dackell (13).
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Exercises
1. Choose another simple random sample of 4 from
the Canadiens hockey players starting at line 103.
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2. You want to survey people about the recent election
in the greater Montreal area. Let’s say there are 25
electoral districts in the greater Montreal area.
Choose an SRS of 5 districts using line 110 of the
Random Digit table. Explain each step.
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