Stats Chapter 2 Flashcards

Study Notes

Data Representation in Statistics

An ordered array lists data in a sequence from largest to smallest or smallest to largest.
Distribution describes the arrangement or structure of a dataset or population.

Frequency Distributions

A frequency distribution shows values in a dataset along with their occurrence frequency.
An ungrouped frequency distribution represents each category with a single value.
A grouped frequency distribution organizes data into ranges instead of individual values.

Frequencies and Classes

Frequencies (f) denote the number of occurrences within categories of a frequency distribution.
A class defines a category in a frequency distribution.

Constructing a Frequency Distribution

Determine the number of classes, typically between 5 and 20.
Select an appropriate class width by dividing the range of data by the number of classes.
Establish class limits by using the minimum data value as a lower limit for the first class, ensuring no overlap occurs.
Count occurrences to find the frequency for each class.

Class Limits and Width

Lower class limit is the minimum value for a class, while the upper class limit is the maximum value.
Class limits should maintain consistent decimal places relative to the dataset.
Class width is the difference between the limits of two consecutive classes.

Creating Frequency Distributions

Begin with the class width to organize data, using the highest and lowest values.
A class boundary is computed as the midpoint between the upper limit of one class and the lower limit of the next.

Midpoints and Relative Frequency

Class midpoint is calculated using the formula: (Lower Limit + Upper Limit) / 2.
Relative frequency represents the proportion or percentage of data within a class, given by the formula: Relative Frequency = f/n, where f is class frequency and n is the total sample size.

Summation Notation

The symbol ∑ denotes the summation of the following values and is represented by the uppercase Greek letter sigma.

Description

Test your knowledge with these flashcards covering key concepts from Statistics Chapter 2. Each term is defined clearly to help reinforce understanding of ordered arrays, distributions, and frequency distributions. Perfect for exam preparation or quick review!