Exam 2: Descriptive Statistics Flashcards
Descriptive Statistics
Methods for summarizing and organizing data derived from a sample.
Population
The entire group of individuals or instances a researcher wants to study.
Sample
A subset of the population selected for the study.
Mean
The arithmetic average of a set of numbers, sensitive to extreme values.
Median
The middle value in a set of numbers, resistant to outliers.
Mode
The most frequently occurring value in a dataset.
Range
The difference between the highest and lowest values in a dataset.
Variance
The average of the squared differences from the mean.
Standard Deviation
The square root of the variance, indicating how spread out the data is.
Normal Distribution
A symmetrical, bell-shaped distribution where most data points cluster around the mean.
Skewed Distribution
A distribution that is not symmetrical, where one tail is longer than the other.
Positively Skewed
A distribution with a long right tail, where the mean is greater than the median.
Negatively Skewed
A distribution with a long left tail, where the mean is less than the median.
Histogram
A graphical representation of the frequency distribution of continuous data, using bars.
Frequency Distribution
A table or graph that shows how often different values occur in a dataset.
Outlier
An extreme value that differs significantly from other values in the dataset.
Correlation
A measure of the strength and direction of the relationship between two variables.
Effect Size
A quantitative measure of the magnitude of a difference or relationship.
Central Tendency
A measure that represents the center or typical value in a dataset (mean, median, mode).
Inferential Statistics
Methods used to make inferences or predictions about a population based on data from a sample.
