Business Statistics

Honelako gehiago

Mean, Median, Mode, and Range

by Mandi Turner

CBM

by adli adzani mohd aziyan

IRRITABLE BOWEL SYNDROME

by Madison McKinlay

Probability and Counting Chart

by Sarah Schuelke

Business Statistics

Topic 1: Introduction

Types of Organisation of Data

Contingency Table, Frequency Distribution

Types of variables

Qualitative (Non-numeric), Quantitative (numeric): Discrete or Continuous

Basic Terms

Population (N), Sample (n)

Subdivisions

Inferential/Descriptive Stats

Topic 2: Statistical Measures

Dispersion

1. Range 2. Variance: Population and sample 3. Standard Deviation: Population and Sample

Central Tendency

Median, Mode

Sample Mean (Ungrouped Data): ¯x = (∑x)/n

(Grouped Data): ¯x = (∑fx)/n

Population Mean (Ungrouped data): μ=(∑x)/N

(Grouped Data): μ=(∑fx)/N

Topic 3: Regression & Correlation Analysis

Linear Regression

Y’ = a + bX

Correlation Analysis

Coefficient of Determination (r2)

Coefficient of Correlation (r)

Negative, Positive, or No correlation

Topic 4: Probability Concepts

Rules

1. Complement Rule 2. General Addition Rule - Intersection of 2 events - Union of 2 events - General Addition Rule - Mutually Exclusive Events 3. Conditional Probability 4. Multiplication Rule

Terms: Experiment, Outcome, Sample Space, Event

Topic 5: Continuous Probability Concepts

Finding z-value z=(x-µ)/σ

Finding z-v

Characterisitcs of Normal Distribution 1. σ = 1, μ=0 2. Disitribuition is symmetrical 3. Area under curve = probability 4. Area under curve = 1

Normal Distribution: Mean = Median = Mode

Topic 9: Chi-Square Distribution

Test Statistics: x2 =∑[(f_o-f_e )^2/f_e ]

H0: There is no difference between fo and fe H1: There is a difference between fo and fe

Types of Testing 1. Goodness-of-Fit Test

Characteristics: 1. x2 values are non-negative 2. postively skewed 3. when degree of freedom changes, new distribution

Topic 8: Hypothesis Testing

Hypothesis Testing: Right-tailed, Left-tailed, Two-tailed

5 Steps 1. State null and alternate hypothesis 2. State level of significance 3. Identify test distribuition and calculate Test Statistic 4. Make a Decision Rule 5. Make a decision - Reject null, accept alternate - Do not reject null

hypothesis: statement or assumption

Topic 7: Confidence Interval

Conditions

Population Normal?

Yes

Is σ known?

Yes, use z-distribution

No, Is n≥30?

Yes (CLT), Use z-distribution

No, Use t-distribution

No

Is n≥30?

Yes(CLT)

Use z-distribution

Interval Estimate: Uses intervals for estimation

Point Estimate (PE): Uses one value for estimation

's' is the PE of population standard deviation

sample mean is the PE of population mean

Topic 6: Sample Probabilities

Conditions of sample mean to be normal

Normal distribution (regardless of sample size)

Distribution unknown, n≥30

Central Limit Theorem (CLT): If the sample size is more than 30, the shape of the sampling distribution of the sample mean is close to a normal probability distribution.