カテゴリー 全て - variance - probability - mean - sampling

によって kim c 2年前.

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Business Statistics

Statistical measures and probability concepts are crucial in analyzing data and drawing meaningful conclusions. Measures of central tendency, such as the mean, median, and mode, help summarize data sets.

Business Statistics

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.