click below
click below
Normal Size Small Size show me how
STA CH 1
CH 1
| Question | Answer |
|---|---|
| Statistics | Is the science of data |
| Two branches of statistics? | Descriptive statistics,Inferential statistics |
| Descriptive Statistics | Consists of the collection, organization, summarization, and presentation of data |
| Inferential Statistics | Consists of generalizing from samples to populations by.. Performing estimations and hypothesis tests,Determining relationships among variables,Making predictions, Uses probability( the chance of an event occurring) |
| Population | Consists of all subjects (human or otherwise) that are being studied. |
| Sample | Is a group of subjects selected from a population. |
| Variable | Is a characteristic or attribute that can assume different values. |
| Data | are the values (measurements or observations) that the variables can assume. |
| Random variable | variables whose values are determined by chance. |
| Types of Data | Variables can be classified as qualitative or quantitative |
| Qualitative | variables that can be placed into distinct categories, according to some characteristic or attribute |
| Quantitative | variables that are numerical and can be ordered or ranked |
| Qualitative Variables | Categorical, Can be further classified into two groups, nominal and ordinal |
| Nominal Data | data can be classified into mutually exclusive (non-overlapping) categories in which no order or ranking can be imposed. |
| Ordinal data | can be classified into categories that can be ranked or ordered |
| Quantitative Variables | Numerical,Can be further classified into two groups, discrete and continuous. |
| Discrete variables | can be assigned values such as 0, 1, 2, 3 and are said to be countable. Obtained by counting |
| Continuous variables | can assume an infinite number of values in an interval between two specific values. Obtained by measuring |
| inferential statistics goal | learn about a population by using a sample |
| unbiased samples | Each subject in the population has an equally likely chance of being selected. |
| Observational study | the researcher observes what is happening (or what has happened in the past) and tries to draw conclusions based on these observations. |
| Experimental study | the researcher manipulates one of the variables and tries to determine how the manipulation influences other variables. |
| independent variable | one that is being manipulated by the researcher |
| dependent variable | the outcome |