Question | Answer |
Raw Data | Data in original form or unorgranized information. |
Frequency Distribution | The organization of raw data in table form, using classes and frequencies. |
Class | Each raw data is placed into a quantitative or qualitative category. |
Frequency | The number of data values contained in a specific class. |
Categorical Frequency Distribution | Is used for data that can be placed in specific categories, such as nominal- or ordinal-level data. |
Class Limits | The upper and lower values of a class for a grouped frequency distribution. Should have the same decimal value as the data. |
Grouped Frequency Distribution | When the range of the data is large, the data must be grouped into classes that are more than one unit in width. |
Class Boundaries | Should have one additional place value than the data value and end in a 5. |
Class Width | The difference between the upper class boundary and the lower class boundary for a class in a frequency distribution. |
Class Midpoint | Is obtained by adding the lower and upper boundaries and dividing by 2. |
Open-Ended Distribution | A frequency distribution with an open-ended class. |
Cumulative Frequency Distribution | A distribution that shows the number of data values less than or equal to a specific value (usually an upper boundary). The values are found by adding and the frequencies of the classes. |
Ungrouped Frequency Distribution | When the range of the data values is relatively small, a frequency distribution can be constructed using single data values for each class. |
Histogram | A graph that displays the data using contiguous vertical bars (unless the frequency of a class is 0) of various heights to represent the frequencies of the classes. |
Frequency Polygon | A graph that displays the data by using lines that connect points plotted for the frequencies at the midpoints of the classes. The frequencies are represented by the heights of the points. |
Ogive | A graph that represents the cumulative frequencies for the classes in a frequency distribution. |
Relative Frequency Graphs | A graph using proportions instead of raw as frequencies. |
Bell -Shaped Distribution | Has a single peak and tapers off at either end. It is approximately symmetric. |
Positively or Right Skewed | The peak of a distribution is to the left and the data values taper off to the right. |
Negatively or Left Skewed | The peak of a distribution is to the right and the data values taper off to the left. |
Bar Graph | Represents the data by using vertical or horizontal bars whose heights or lengths represents the frequencies of the data. |
Pareto Chart | Used to represent a frequency distribution for a categorical variable, and the frequencies are displayed by the heights of vertical bars, which are arranged in order from highest to lowest. |
Time Series Graph | Represents data that occur over a specific period of time. |
Pie Graph | A circle that is divided into sections or wedges according to the percentage of frequencies in each category of the distribution. |
Stem and Leaf Plot | A data plot that uses part of the data value as the stem and part of the data value as the leaf to form groups or classes. |
Scatter Plot | A graph or order pairs of data values that are used to determine if a relationship exists between the two variables. |
A Positive Linear Relationship | Exists when the points fall approximately in an ascending straight line and both the x and y values increase at the same time. |
A Negative Linear Relationship | Exists when the points fall approximately in a descending straight line from left to right. |