Transcript Population and Sample

Objective
To distinguish between a sample and a population
Purpose/Relevance
To understand how a statistical study using a sample can be
used to describe a population
PRETEST
POPULATION
The entire collection of individuals about
which information is desired.
SAMPLE
Subset of the population from which we actually
collect the information.
Used to draw conclusions about the population
Population
Collect data from a
representative Sample...
Sample
Make an Inference about the
Population.
GIVE THE POPULATION & SAMPLE.
Favorite class of all T. L. Hanna students.
Survey people to find out who they will vote for.
Test the strength of ropes – 1 per hour.
A COMPANY EMPLOYS 800 INDIVIDUALS. TO
DETERMINE HOW THE EMPLOYEES FEEL ABOUT THE
NEW INSURANCE PLAN, 80 OF THE EMPLOYEES ARE
SURVEYED.
*Describe the population:
*Describe the sample:
WE WANT TO DETERMINE THE PERCENTAGE OF
SOUTH CAROLINA VOTERS WHO WILL VOTE FOR
HILARY CLINTON IN THE NEXT ELECTION IF THE
ELECTION TOOK PLACE TODAY.
*Describe the population:
*Describe the sample:
IDENTIFY THE POPULATION & THE SAMPLE:
A furniture maker buys hardwood in large batches.
The supplier is supposed to dry the wood before
shipping (to keep it’s size and shape). The
furniture maker chooses five pieces of wood from
each batch and tests their moisture content. If any
piece exceeds 12% moisture content, the entire
batch is sent back.
IDENTIFY THE POPULATION & THE SAMPLE:
Each week, the Gallup Poll questions a sample of
about 1500 adult U. S. residents to determine
national opinion on a wide variety of issues.
DESCRIBE THE POPULATION & SAMPLE.
A consumer group conducts crash tests of new model
cars. To determine the severity of damage to 2003
Mazda 626’s resulting from a 10-mph crash into a
concrete wall, the research group tests six cars of this
type and assesses the amount of damage.
FISH TAG
LAB
HOMEWORK
*Worksheet – Population & Sample