STATS: Lesson 3: Methods of Organizing and Presenting Data

Grouped Data

The type of data which is classified into groups after collection.

Ungrouped Data

Also known as raw data is data that has not been placed in any group or category after collection.

1. By forming an array

2. By making a stem-leaf plot

3. An ungrouped frequency distribution

Ways of Organizing Ungrouped Data

Data Array

Forming a _____ means organizing a set of raw, ungrouped data into an ordered sequence from lowest to highest (ascending) or highest to lowest (descending). This simple arrangement helps you quickly spot the range, minimum, and maximum values.

Frequency Distribution Table (FDT)

is a way to show frequencies in an organized way.

Ungrouped frequency distribution

used when there is a small number of observations

Grouped frequency distribution

a statistical table that organizes a large set of continuous or numerical data into smaller, equal sized groups called class intervals.

Class Intervals (Classes)

The grouped ranges or bins that divide up the data

Class Width

The size or difference between the lower limit of one class and the lower limit of the next class.

Frequency (𝒇)

The number of data points that land inside a specific class interval.

Class Mark (Midpoint)

The center value of a class interval, calculated as (Lower Limit + Upper Limit)/2

cumulative frequency

refers to subtotals obtained from the successive additions of the frequencies. This may be done in two ways:

less than cumulative frequencies (<cf)

refer to the frequencies added successively from the lowest class interval to the highest class interval.

greater than cumulative frequencies (>cf)

refer to the frequencies added successively from the highest class interval to the lowest class interval.

relative frequency

is the ratio of the individual frequency per class to the total number of cases (n) then multiplied by 100%. The formula is: (rf) = 𝑓 𝑛 𝑥 100%

1. Textual Method

2. Tabular Method

3. Graphical Presentation

PRESENTATION OF DATA

1. Pie Charts/Diagram

2. Horizontal Bar Charts

3. Vertical Column Charts

4. Line Charts

5. Pictogram

Types of Graphs

Textual Method

Data incorporated to a paragraph of text

Tabular Method

The systematic organization of data in rows and columns.

Graphical Presentation

Presentation of data in the form of a graph or diagram

pie chart

Use the _______ when considering displaying one set of data as part of a whole, or when a main item is divided into several categories.

Horizontal bar charts

are used to illustrate comparisons among individual items. Sometimes, pictures are used to substitute the bars. Such graphs are called pictographs.

Vertical Column Charts

are useful in showing data changes over a period of time or for comparing among several items.

line graphs

are used to display data across a period of time. The emphasis of line charts are not the actual values, but the trend or movement of the data across time.

Pictogram (or pictograph)

a visual chart or diagram that uses small pictures, icons, or symbols to show and compare numbers or data