Statistics fall review

Front

What is a random sample?

Back

A random sample is a subset of individuals chosen from a larger set, where each individual has an equal chance of being selected, ensuring that the sample represents the population accurately.

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean of a data set. It is calculated as (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

What is the purpose of random assignment in experiments?

Back

The purpose of random assignment is to create roughly equivalent groups before treatments are administered, which helps to eliminate bias and confounding variables.

Front

What are categorical variables?

Back

Categorical variables are variables that represent categories or groups and can be divided into nominal (no order) and ordinal (with order) types.

Front

What are quantitative variables?

Back

Quantitative variables are numerical variables that can be measured and expressed as numbers, allowing for mathematical operations.

Front

What is a pie chart?

Back

A pie chart is a circular statistical graphic divided into slices to illustrate numerical proportions, where each slice represents a category's contribution to the whole.

Front

What is the mean?

Back

The mean is the average of a set of numbers, calculated by adding all the values together and dividing by the number of values.

Front

What is the median?

Back

The median is the middle value in a data set when the numbers are arranged in ascending or descending order. If there is an even number of observations, the median is the average of the two middle numbers.

Front

What is the mode?

Back

The mode is the value that appears most frequently in a data set. A set may have one mode, more than one mode, or no mode at all.

Front

What is bias in statistics?

Back

Bias refers to systematic errors that lead to incorrect conclusions or results in statistical analysis, often due to flawed sampling methods or data collection.