Examples of everything

Whether a person classifies him or herself as a political, conservative moderate, or liberal

Categorical

Whether a toliet baper roll is hung so that the paper comes out over the top or underneath

Categorical (binary)

what is the observational unit in this question

The nellie mae organization conducts an extensive annual study of credit card usage of college students

The owners of a sports stadium wanted to predict what additional refreshment options would sell well. They selected 80 seat numbers at random and surveyed the occupants of those seats.

The population is the occupants of all seats in the sports stadium; the sample is the occupants of the 80 selected seats.

is this a variable or not- what is your eye color?

Yes it is a variable

Whether or not you have a credit card

categorical (binary)

is this a variable or not- do men have to wait longer in the waiting room vs women

not a variable

How many hours have you slept the past 24 hours

quantatative

Ratio of backpack weight to body weight of college student

quantatative

how many states you visited

quantatative

A safety inspector conducts air quality tests on a randomly selected group of 7 classrooms at an elementary school. what is population and sample

sample: 7 population: classrooms at elementary school

A pediatrician randomly selected 10 parents of his patients. Then he surveyed the parents about their opinions of different kinds of diapers. what is population and sample

sample:10 parents of patients population: parents of pediatricians patients

A quality control engineer is curious about the thickness of paint on a car at her factory. She randomly selects 30 points on the car and measures the paint thickness at each of those points. what is population and sample

sample:30 Population: The population is every possible point on the car

what is the observational unit in this question

suppose you want to investigate whether or not students who sit closer to teacher tend to score higher on quizzes then students who sit further away

is this a variable or not- what is your blood type?

yes it is a variable you can ask everyone their blood type

is this a variable or not- What is your waiting time

yes this is a variable