Normal Curve and Z-scores_default

Normal Curve

A theoretical bell-shaped curve that represents the distribution of a variable, symmetric around the mean.

Gaussian Distribution

Another name for the normal distribution, named after mathematician Carl Friedrich Gauss.

Z-Score

A measure of how many standard deviations an individual score is from the mean of the distribution.

Standard Deviation

A measure that quantifies the amount of variation or dispersion in a set of values.

Mean

The average of a set of numbers, calculated by summing the values and dividing by the count.

Outlier

A data point that significantly differs from other observations in the dataset.

Inferential Statistics

Statistical methods that allow for making inferences about a population based on a sample.

Area Under the Curve (AUC)

In probability distributions, it represents the total probability, equal to 1.

Deviation Score

The difference between an individual score and the mean of the distribution.

68-95-99.7 Rule

States that 68.2% of data falls within one standard deviation, 95.4% within two, and 99.7% within three standard deviations of the mean.

Probability Distribution

A mathematical function that provides the probabilities of occurrence of different possible outcomes.

Symmetry in Normal Distribution

In a perfect normal distribution, the left side and right side are mirrored and have the same shape.

Continuous Distribution

A probability distribution that shows the probabilities of the possible values of a continuous random variable.

Standard Normal Distribution

A normal distribution with a mean of 0 and a standard deviation of 1.

Z-Table

A table that shows the cumulative probability of a standard normal distribution for different Z-scores.

Percent Probability

The likelihood of an event occurring, expressed as a percentage.