Introduction To Statistics

Data is everywhere.

Information from observations, counts, measurements, or responses.

The science of collecting, organizing, analyzing, and interpreting data.

A number which describes a characteristic of a population.

A number which describes a characteristic of a sample.

Descriptive and Inferential

The organization, summarization, and display of data.

Uses a sample to find conclusions, analyzations, and probability about a population.

Because it is more difficult to get an accurate population where as a sample is smaller and easier to assess.

To put in order (good, better, best).

Nominal and Ordinal

Interval and Ratio

To list based on names.

Qualitative and quantitative

To find the mathematical difference. Including temperatures and dates.

To find a ratio between two things. Including weight and time.

Observation, Experiment, Surveys, and Simulations.

Study where you observe and record the outcome of a variable. Relatively easy to perform and can show correlation but not causation because of confounding variables.

Doctors in the 50's noticed that there was a correlation between smoking and lung disease.

Study where you impose a treatment and record the outcome and compare outcomes with a control group. Can show causation (may be difficult due to ethical/physical complications).

At a college, ½ got laptops, ½ got paper for notes, the ones with paper did better on the test.

Ask a random sample of subjects well worded questions and record responses. Difficult to avoid bias.

Using technology to simulate an actual event. Used when the event would be too dangerous or too expensive to do in real life.