Statistical Tools for Decision-making Questions with 100% correct Answers 2024

Statistical Tools for Decision-making Questions with 100% correct Answers 2024 What is statistics? an instrument that observes a set of units to draw conclusions about collective phenomena Why do we need statistics? 1) we are not all the same 2) world is complex 3) we easily make mistakes in observing reality How do we bring meaning to raw data? 1. Description 2. Comparison 3. Inference 4. Risk assessment and other probability-related events 5. Identifying important relations (associations - statistical detective work) Types of Statistics 1. Descriptive 2. Inferential Descriptive statistics statistics that presents, organises and summarises the data collected in a study Inferential statistics statistics that allows us to generalise and draw conclusions about larger populations from small samples of data Population a set of similar items or events which is of interest to some questions or experiments Sample set of data collected and/or selected from a population by a defined procedure. Sample points /sampling units or observations Elements of a sample Variable A factor that can change (characteristic of a person, object, event which can have different values.) Variables are what is being measured and observed. Kinds of variables 1. independent 2. dependent Types of variables 1. Qualitative 2. Quantitative Dependent Variable (DV) The measured outcome of a study; the responses of the subjects in a study. (the effect) Independent Variable (IV) the factor the researcher manipulates in a controlled experiment (the cause) Qualitative Variable a categorical variable, those that cannot be described with numbers Quantitative Variable variable or a characteristic that can be measured numerically Kinds of qualitative variables 1. Ordinal 2. Nominal Kinds of quantitative variables 1. Continuous 2. Discrete continious variable any real number (possible numbers with decimals) Discrete only integer numbers (number without decimals) Discrete variable can be continuous when you compute the mean (17 people in each room - how many people per room) ordinal variable a qualitative variable that incorporates an ordered position, or rankin