In a graphical reprensentation of data, the largest numerical value is...
Finding Class Intervals in a Graphical Representation of Data
To find the class intervals in a graphical representation of data, follow the steps below:
Step 1: Find the Range
The range is the difference between the largest and smallest numerical values in the data set. In this case, the range is:
Range = Largest value - Smallest value = 4 - 25 = -21
Step 2: Determine the Number of Classes
The number of classes desired is given as 4 in the question.
Step 3: Calculate the Class Interval
The class interval is calculated using the formula:
Class Interval = Range / Number of Classes
Plugging in the values from our example:
Class Interval = -21 / 4 = -5.25
However, class intervals cannot be negative, so we need to use absolute values.
Class Interval = | -5.25 | = 5.25
Step 4: Determine the Class Boundaries
To determine the class boundaries, we need to start with the smallest numerical value in the data set, which is 25.
Class Boundaries:
- Class 1: 25 - 20.75
- Class 2: 20.75 - 16.5
- Class 3: 16.5 - 12.25
- Class 4: 12.25 - 8
These class boundaries result in class intervals of 4.25, which is close to our desired class interval of 5.25.
Therefore, we can round up or down the class boundaries to get the desired class interval.
Note: It is important to choose class boundaries that are easy to work with and understand.