Sample/ Probability

Population: Universe of events (ex- patients with aids, red wing birds) 

Rarely able to obtain data from every subject- the solution is samples 

Samples- subsets drawn from a population

Techniques- 

Random- every subject has same probability of being selected (Ex- table, coin flip, drawing straws) 

Systematic- predetermined method (Ex- every 3^rd, every 4^th) 

Convince - obtain under financial constraints

Probability-  the chance or likelihood that an event will occur

Theoretical- chances an event will occur (Ex- coin flip 50%) 

Empirical- based on data collection (Ex- HTHHTTHH) 

Frequency distribution- 

Exploratory Data analysis (EDA) 

-     Used to count frequency of occurrence of each datum in a sample population 

-     Search for trends/ patterns 

Displaying results- frequency distribution 

·     Pie Chart 

·     Bar Chart 

·     Histogram 

·     Relative Frequency – (pie chart/ stacked graph)