Samples and Populations (Unit 5)

Which one of the following sampling methods would give unbiased results, if you need to find out the number of people in your town liking vanilla or chocolate ice creams? A. ask my neighbors B. randomly select a few ice cream shops in town, and question people coming there C. ask my friends D. ask my classmates

Answer: B.

Random sample

In a random sample, each individual in the population has an equal chance of being part of the sample

Random samples

In a random sample, each indiviusal in the populaiton has an equal chance

Representative sample

Is a portion of the population that is similar to the entire population

Survey

Is a question or set of questions used to gather data

Sample

Is a smaller group taken from the population

Biased sample

Is one in which some members of the population have a greater chance of being selected

Unbiased sample

One in which NO members of the population have a greater chance of being selected

A pediatrician randomly selected 101010 parents of his patients. Then he surveyed the parents about their opinions of different kinds of diapers. Identify the sample and population

The population is the parents of the pediatrician patients; The sample is the 10 parents of patients selected.

A factory overseer selects 404040 threaded rods at random from those produced that week at the factory, then she tests their tensile strength. Identify the sample and population.

The population is threaded rods produced at the factory that week; The sample is the 40 threaded rods selected

Reggie thinks that more students in his school are right-handed than left-handed. He surveys the students in his class and finds that 23 of the students are right-handed. Do the results of Reggie's survey support his inference that more students in his school are right-handed than left-handed?

The results of Reggie's survey support his inference that more students in his school are right-handed that left-handed

What are the differences between voluntary response sampling, Response bias.

Voluntary response bias occurs when there sample is responding to the question without being randomly selected. Response bias is a systematic pattern of incorrect responses in a sample survey.

Population

is the group of intrest