Fundamentals of Descriptive Statistics

Flashcards for reviewing descriptive statistics concepts.

What is the importance of uncertainty and variation in statistics?

They highlight the need for informed judgments and decisions, making statistical methods and statisticians necessary.

What is variability in statistics?

The inherent differences or fluctuations in a quantity.

What is uncertainty in statistics?

The degree of precision with which a quantity is measured, affected by measurement limitations or errors.

Why do data exhibit variability and uncertainty?

Due to unpredictable phenomena, measurement errors, and conclusions drawn from samples instead of entire populations.

What is a population in statistics?

The entire collection of individuals, objects, or outcomes about which data are collected.

What is a sample in statistics?

A subset of the population that contains the observed individuals or outcomes, used to make inferences about the broader population.

What is a variable in statistics?

A characteristic under study that can take different values for different elements.

What is a qualitative variable?

A variable whose variants are expressed verbally as names or labels.

What is a nominal variable?

A qualitative variable with distinct, unordered categories.

What is an ordinal variable?

A variable representing a transition between qualitative and quantitative variables where categories can be ordered or ranked.

What is a quantitative variable?

A variable that can be measured numerically.

What is a discrete variable?

A quantitative variable with a finite or countable number of values.

What is a continuous variable?

A quantitative variable that can assume any numerical value within a certain interval.

What is the Sturges formula used for?

Determining the optimal number of intervals for representing a continuous distribution. K = 1 + (10/3)log(n)

What are raw data?

Data recorded in the order they are collected before any processing or ranking.

What are grouped data?

Data presented in the form of a frequency distribution table.

How do you calculate the midpoint of an interval?

𝒙𝒊 = (𝑙𝑜𝑤𝑒𝑟 𝑙𝑖𝑚𝑖𝑡 + 𝑢𝑝𝑝𝑒𝑟 𝑙𝑖𝑚𝑖𝑡) / 2