Statistical Methods in Quality Management

Flashcards covering key concepts in statistical methods relevant for quality management.

Descriptive Statistics

Methods of presenting data visually and numerically, including charts, frequency distributions, and measures of central tendency.

Statistical Inference

The process of drawing conclusions about unknown characteristics of a population from which data were taken.

Population

A complete set or collection of objects of interest.

Sample

A subset of objects taken from a population.

Mean

The average value of a population or sample, calculated as the sum of all observations divided by the number of observations.

Median

The middle value in a sorted data set.

Mode

The most frequently occurring observation in a data set.

Variance

A measure of how much values in a data set differ from the mean value; calculated differently for populations and samples.

Standard Deviation

A measure of the amount of variation or dispersion in a set of values, calculated differently for populations and samples.

Skewness

A measure of the lack of symmetry in a data distribution.

Kurtosis

A measure of the 'peakedness' or flatness of a histogram.

Simple Random Sampling

A sampling method where every member of the population has an equal chance of being selected.

Stratified Sampling

A sampling method that involves dividing the population into homogeneous subgroups and selecting samples from each.

Central Limit Theorem

States that the sampling distribution of the mean will be normally distributed if the sample size is large enough.

Confidence Interval

An interval estimate of a population parameter that specifies the likelihood that the interval contains the true population parameter.

Hypothesis Testing

A method of making statistical decisions about the value of a population parameter based on sample data.

ANOVA (Analysis of Variance)

A hypothesis-testing methodology used to determine if there are any statistically significant differences between the means of three or more independent groups.

Regression Analysis

A statistical method for modeling the relationship between a dependent variable and one or more independent variables.

Coefficient of Determination (R^2)

A measure that explains the proportion of variance in the dependent variable that is predictable from the independent variable(s).