The document explains key concepts in statistics including populations, samples, parameters, and statistics, with definitions and examples. It distinguishes between descriptive statistics, which summarize sample data, and inferential statistics, which estimate population parameters based on sample data. Overall, it emphasizes the importance of understanding how to categorize and analyze data in the field of statistics.

1. Mastering Statistics
Mean, Std Deviation, Variance, Z-score, Sampling

2. Lesson 2 – Populations and Samples - definitions
 Statistics: Gathering, describing & analysing data. OR numeric description of sample data
 Data: Information Gathering
 Population: Particular group of interest ex: everybody in a city; everybody in something,
 ex: all males or all females, all children between 6-9 ya, ex: everybody in a city; .
 Note the word ALL, is all inclusive of a category
 Parameter: Numerical description of a population characteristic
 Ex: the mean height of all males in the world; IQ of all children in the world, mean IQ of all females in USA, 75% of all kids age
6-9 play games
 Note the word NUMERICAL from definition; it is a number
 Sample: Subset of the POPULATION from which DATA is collected
 Ex: we asked 100 males IN THE CITY what their fav movies
 Sample Statistic: Numeric description of particular sample CHARACHTERISTIC
 Ex: 100 female asked from city; 47% disliked chocolate

3. Lesson 3 – Descriptive vs Inferential Statistics
Branches of statistics
 Descriptive Statistic – gather, sort, summarise data from sample
 Inferential statistics – use descriptive statistics (DATA) to ESTIMATE POPULATION PARAMETERS
 Problem: Based on a phone survey, 22% of all men dislike football
 Inferential as we estimate the percentage of a population from a sample (survey)
 PR2: 65% of seniors at a local HS apply to college plan to major in business
 Descriptive because
Population
Sample

4. Lesson 4 – Apply Definitions in Statistics
 Height of every 4th bottle on an assembly line: Sample
 Ages of all USA president: Population
 A research stop 100 people in a store to ask a survey of household income
 Population: people in a store
 Sample: 100 people chosen
Parameters describe populations, statistics describe sample
 The average number of hour per week a sample of 10 yo. spend watching TV is 20h
 Statistic: 20h/week for the sample
 87% of all patients in a hospital report having alcohol problem.
 Parameter: describe all patients