What is the difference between a sample and a population?

A ​ (a)   is a set of all items or events which are of interest for some question or experiment.

It is generally the group you are trying to make predictions or learn something about.

For most studies, it is either impossible or impractical to obtain data on an entire population.

This is why you need to use a smaller selection of items.

A ​ (b)   is a selection of observations from a population.

We measure data in a known sample to make a prediction, or inference, about the population.

• population

• correlation

• sample

• causation

• ideation

• application

• understudy

• sample survey

• experiment

• observational study

Complete the chart by choosing Observational Study (Obs), Experiment (Exp), both, or neither for the following statements:

• Experiment (Exp)

• Neither

• Observational Study (Obs)

• Both

What is the typical cutoff for a correlation showing a “strong” linear relationship?

|r| > _.__

Mathematical Equivalence

ON

Which of these samples is likely to be the LEAST accurate estimate for the height of students in your class and why?

• The girls in your grade because girls are usually shorter than boys.

• The students in the other class because their height would not be exactly the same as the heights of students in your class.

• Your friend group because your friends are all similar heights as each other.

• Just you because there would be only one data point.

_______ is the entire group of objects or individuals considered for a survey.

• Sample

• Population

• Random Sample

• Quartile

The entire group studied.

• sample

• population

What is the entire group of individuals or instances studied called?

• sample

• population

• class

• experiment

A survey is carried out at Penn State Altoona to estimate the proportion of all undergraduate students living at home during the current term. Of the 3,838 undergraduate students enrolled at the campus, a random sample of 100 was surveyed. What is the population of the study?

• All the 3,838 undergraduate students enrolled at the campus

• The 100 who were surveyed

• All the students in universities across America

• All students living at home in the current term.

What is the entire group studied called?

• sample

• population

• class

• experiment

What is the approximate correlation coefficient, r, for these two variables?

Round to the nearest thousandth.

(To find r, calculate the square root of R² to find the magnitude of r and then decide if it should be positive or negative based on the data.)

Mathematical Equivalence

ON