Business Statistics Intro Flashcards
Define Statistics
Statistics is the branch of mathematics that examines ways to process and analyse data. Statistics provides procedures to collect and transform data in ways that are useful to business decision makers. To understand anything about statistics, you first need to understand the meaning of a variable.
4 fundamental terms of statistics
Population
Sample
Parameter
Statistic
Population
A population consists of all the members of a group about which you want to draw a conclusion.
Sample
A sample is the portion of the population selected for analysis
Parameter
A parameter is a numerical measure that describes a characteristic of a population
Statistic
A statistic is a numerical measure that describes a characteristic of a sample (measures calculated from sample data) ROMAN LETTERS REFER TO
STATISTICS
What are the 2 types of statistics?
Descriptive statistics
Inferential statistics
Descriptive statistics
Collecting, summarizing and presenting data
Inferential statistics
Drawing conclusions about a population based on sample data/results (i.e. estimating a parameter based on a statistic)
3 steps of descriptive statistics
Collect data (ex. survey) Present data (ex. tables and graphs) Characterize data (ex. sample mean)
Steps of inferential statistics
Estimation (ex. estimate the population mean weight (parameter) using the sample mean weight (statistic)) Hypothesis Testing (ex. test the claim that the population mean weight is 100 kilos)
4 important sources when collecting data
Data distributed by organisation or individual
Designed experiment
Survey
Observational study
2 classifications of data sources
Primary
Secondary
2 types of data
Categorical (defined categories)
Numerical (quantitative)
2 types of numerical variables
Discrete (counted items)
Continuous (measured characteristics)
Categorical data
Simply classifies data into categories (e.g. marital status, hair colour, gender)
Numerical discrete data
Counted items – finite number of items (e.g. number of
children, number of people who have type-O blood
Numerical continuous data
Measured characteristics – infinite number of items
e.g. weight, height
4 Levels of Measurement and Measurement Scales from highest to lowest
Ratio data
Interval data
Ordinal data
Nominal data
Ratio data
Differences between measurements are meaningful and a true zero exists
Distance, area, height, weight, age, weekly food spending
Interval data
Differences between measurements are meaningful but no true zero exists
Year, temperature in degrees Celsius, standardized exam score
Ordinal data
Ordered categories (rankings, order or scaling)
Rankings in a tennis tournament, student letter grades, Liker scales
Nominal data
Categories (no ordering or direction)
Gender, eye color, hair color,
