
What sampling method is used?
A statistician who makes a research on automobile performance collects
information on American, Japanese, and European automobiles separately
to combine the results in the end.
Stratified

What sampling method is used?
An inspector team from
Department of Education needs to inspect middle schools in a large
city. They choose at random 10 schools and then come to each of them to
inspect each class.
Cluster

What sampling method is used?
An inspector came to a public
school to survey the teachers. She comes to the teacher lounge during
the lunch break and talks with every present teacher.
Convenience

What sampling method is used?
A quality control manager picks every 100th soda can, opens it and measures the amount of drink in it.
Systematic

Is this an observational or an experimental study?
A farmer applies several new fertilizers to fruit trees to find out which of them is the most efficient.
Experimental

Is this an observational or an experimental study?
A zoologist counts the bees visiting a rose bush during a 3  hour period.
Observational

What level of measurement is this?
The letter grades: A, B, C, D, F.
Ordinal
The data can be arranged in a logical order, but the intervals between them cannot be definded.

What level of measurement is this?
The number of passengers in a bus.
Ratio
We can compare the numbers of passengers in different buses by dividing one by the other.

What level of measurement is this?
Your age.
Ratio
We can compare two person's ages by dividing one by the other.

What level of measurement is this
Your year of birth.
Interval
 Years of birth can be compared by subtraction but
 not by division, since there is no natural zero. (Each calendar has it
 different.)

What level of measurement is this?
Numerical equivalents of school grades (4 for A, 3 for b, 2 for C etc.)
Interval
Grades can be compared by subtraction, but dividing them by each other makes no sense.

What level of measurement is this?
The number of teeth in an animals's mouth
Ratio
We can compare the numbers of teeth by dividing one by the other.

What level of measurement is this?
A car's maximum speed.
Ratio
We can compare two car's maximum speeds by dividing one by the other.

What level of measurement is this?
A girl's hair color.
Nominal
Colors are always at the nominal level.

What level of measurement is this?
Your email address
What level of measurement is this?
Your email address

What level of measurement is this?
Condition of a knife (sharp, dull, jagged).
Ordinal
The data can be arranged in a logical order, but the intervals between them cannot be defined.

