Population Sampling

Identify the Population:
Wicomico County Public Schools randomly selected 230 teachers to find out which technology resource it's teachers feel is the most effective.

• 230 Teachers

• All Wicomico County Teachers

• Students

• Wicomico County Public Schools

If I wanted to know how many blades of grass are inside the track, which sampling method could I use?

• Have my students count every blade of grass

• Guess

• Divide the grassy area into 1 inch sections, randomly pick several sections to count, average them together and multiply that by the total square inches.

At a middle school, the 7th graders will conduct a survey to decide where they want to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year

• to randomly choose some 7th grade students to select a location

• to ask all 7th grade teachers and administrators for a location

• to ask the student council to choose a location

Identify the Sample:
A restaurant wants to know if their customers buy dessert when they eat out. As people leave the restaurant one evening, 20 people are surveyed at random. Eight people say they usually order dessert when they eat out. The restaurant concluded that most customers do not order dessert.

• 20 customers

• All customers

• 8 customers

• Dessert

There are 45 people working in a particular building. A survey on dietary habits is conducted by giving every third person in the building a questionnaire to fill out. From the questionnaire, the researcher obtains a score on the dietary habits of the 15 people.What is the number of members in the population?

Mathematical Equivalence

ON

The entire group studied.

• sample

• population

There are 45 people working in a particular building. A survey on dietary habits is conducted by giving every third person in the building a questionnaire to fill out. From the questionnaire, the researcher obtains a score on the dietary habits of the 15 people.

What is the number of members in the population?

Mathematical Equivalence

ON

Population or Sample? 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.

• Population

• Sample

Population or Sample?

A factory overseer selects 40 threaded rods at random from those produced that week at the factory, then she tests their tensile strength.

• Population

• Sample

The entire group studied is called the

• sample

• population