반응형 Study Notes/Statistics6 Normal Distributions 목차 1. Normal Distribution has 2 parameters (=number describing whole population): mean (mu; µ) and varaince (sigma squared; σ^2) they are constants (same value for all observations in the population X ~ N (µ, σ^2) probability of getting a single point X is 0; it is area! Standard Normal Random Variable variable X is transformed to "Z score" mean= 0 and variance = 1 Z ~ N (0,1) X (RV) → Z → proba.. 2022. 11. 25. Probability 확률 목차 Probability Theory 확률 Probability: science of uncertainty 1. Classical Probability Theory [Equal-Likelihood Model] ~ selected “at random” N possible outcomes, event that can occur in f ways P(A) = f/N Experiment: process / situation in which different things can happen Outcome: one of the possible things that can happen Outcome space (sample space): the set of all possible outcomes of an expe.. 2022. 10. 21. Descriptive Statistics 목차 Descriptive (exploratory) Methods organize and summarize data has visual displays of data & calculation of numerical quantities (e.g., mean or median) Variables categorical vs. numerical categorical variables: few values, may or may not have numeric properties (e.g., male or female) numerical variables: many values, recorded as numbers (e.g., time in seconds) OR, qualitative vs. quantitative .. 2022. 9. 21. 2. Standard Deviation 구하는 방법 목차 용어 정리 Population mean μ = Σ ( Xi ) / N Population standard deviation σ = sqrt [ Σ ( Xi – μ )^2 / N ] Population deviation σ^2 = Σ ( Xi – μ )^2 / N Sample mean ˉx = Σ ( Xi ) / n Sample standard deviation s = sqrt [ Σ ( xi – ˉx )^2 / ( n – 1 ) ] Sample deviation s^2 = Σ ( xi – ˉx )^2 / ( n – 1 ) Standard deviation 구하기 if, the sample data is x= {4,8,9,4,5,3,2} * sample mean = ˉx = Σ (Xi) / n = 3.. 2022. 9. 16. 이전 1 2 다음 반응형
