business statistics and excel

Chapter 1: Data and Statistics

Data: Terminology

· Element

· Variable

· Observation

· Scale of Measurement: Categorical vs. Quantitative (Discrete and Continuous)

· Cross-Sectional vs. Time-Series

Data Source

· Primary vs. Secondary

· Interquartile Range

· Variance

· Standard Deviation

· Coefficient of Variation

Statistical Inference

· Population vs. Sample

· What is the process of statistical inference?

· Census vs. Sample survey

Chapter 2: Descriptive Statistics: Tabular and Graphical Displays

Summarizing Data for a Categorical Variable

· Frequency Distribution (Frequency, Relative Frequency, Percent Frequency)

· Using a PivotTable in Excel to easily create the table.

· Bar Chart

· Pie Chart

Summarizing Data for a Quantitative Variable

· First, you should decide the number of groups (classes) to categorize the quantitative variable. Then, Frequency Distribution (Frequency, Relative Frequency, Percent Frequency)

· Using a PivotTable in Excel to easily create the table.

· Histogram

· Quartiles

Summarizing Data for two variables using Tables

· Cross-tabulation (one variable is categorical and the other is quantitative, both variables are categorical, or both variables are quantitative) Note: First, you should decide the number of groups to categorize the quantitate variable if you have a quantitative variable.

· Using a PivotTable in Excel to easily create the table.

· When you have a cross-tab, remember how to compute row percentages and column percentages.

· Standard Deviation

· Coefficient of Variation

Summarizing Data for two variables using Graphs

· Scatter Diagram with Trend-line (only works for two quantitative variables)

· Stacked Bar chart (Two categorical variables, if a quantitative then make groups for the variable =categorization)

· Side by Side bar chat (Two categorical variables)

Chapter 3: Descriptive Statistics: Numerical Measures

Measures of Location

· Mean

· Median

· Mode

· Weighted Mean

· Percentiles

· Quartiles

Measures of Variability

· Range

· Interquartile Range

· Variance

· Standard Deviation

· Coefficient of Variation

Measures of Distribution Shape:

· Skewness

· Z-score

· Empirical Rule

· Detecting outliers

· Five Number summaries

Measures of Association between Two Variables

· Covariance

· Correlation

Chapter 4: Probability

Probability Terminology

· Experiments (meaning of random experiment?), sample point, sample space

Counting Rules (To define the size of a sample space of an experiment)

· Multiple step experiments (Tree diagram)

· Combinations

· Permutation s

Assigning Probabilities (After sample space is defined)

· Basic requirements in probability assignment ( 0<=P(E)<=1, The sum of all probabilities of an experiment = 1)

· Three methods to assign probabilities (Classical method, Relative frequency method, Subjective methods)

Events and Their Probabilities

· An event is a collection of sample points.

· The probability of any event is equal to the sum of the probabilities of the sample points in the event.

Basic Relationship of Probability

· Complement of an event: Ac

· Union of two events: A or B, or A U B

· Intersection of two events: A and B, or A ∩ B.

· Mutually exclusive events: P(A ∩ B)=0

· Addition Law: P(A U B)= P(A)+P(B)-P(A ∩ B)

Conditional Probability

· Multiplication law

· Independent Events

· Two events are independent if or

· Bayes’ Theorem