WGU Intro to Probability and Statistics | 107 Questions and Answers(A+ Solution guide)

Population - The entire group that is the target of interest, not just people. Eg, "the population of 1 bedroom apartments" Sample - A subgroup of the population. Eg, "the 1 bedroom apartments with dishwashers." Steps in the statistics process - 1. PRODUCE DATA (by studying a sample of the population) 2. EXPLORATORY DATA ANALYSIS (Summarize data.) 3. PROBABILITY ANALYSIS (Determine how the sample may differ from the population.) 4. INFERENCE (draw conclusions) Data - pieces of info about individuals organized into variables Individual - a particular person or object Variable - a particular characteristic of the individual Dataset - a set of data identified with particular circumstances. Typically displayed in tables with rows as the individuals and columns as the variables Quantitative vs Categorical/Qualitative variables - Quantitaive: Numerical values. Represent a measurement. Categorical: category or label values into which individuals are grouped. Three steps in Exploratory Data Analysis - 1. Organize and SUMMARIZE raw data 2. DISCOVER important features and patterns and striking deviations. 3. INTERPRET findings in the context of the problemExamining Distributions - exploring data obtained from one variable at a time Examining Relationships - exploring data obtained from two variables at a time Distribution - what values the variable takes, how often Three types of graphical displays of categorical distributions - 1. Pie Charts 2. Bar Charts 3. Pictogram Bins - ranges of data to make charting easier, like a bar chart where each bar shows a range like 70-80% Numerical Summaries - category counts and percentages Four types of Graphical displays of Quantitative Variables - 1. Histogram 2. Stemplot 3. Dotplot 4. Boxplot Histogram - like a bar chart but the x axis is numerical, in order. Eg: x axis is years, y axis is Men's income and Women's income. Or, the x axis is number of hours studied, and y axis is number of students falling into each number of hours studied category.