Lower Class Boundary

The lower extreme point of a class is called the lower class boundary. It is the smallest value that can be included in a particular class. The lower class boundary is used to define the range of values that are included in a given class. It is useful in statistical analysis, particularly for calculating measures such as the mean and standard deviation.

Difference between Lower Class Limit and Lower Class Boundary

The lower class limit is the smallest possible value that can be included in a particular class, while the lower class boundary is the midpoint between the lower class limit of one class and the upper class limit of the previous class. The lower class boundary is always halfway between the lower class limit and the next value.

Example

Suppose we have a data set consisting of the following values: 10, 12, 15, 18, 20, 22, and 25. We want to create a frequency distribution table with five classes. The lower limit of the first class is 10, and the upper limit is 14. The lower limit of the second class is 15, and the upper limit is 19. The lower limit of the third class is 20, and the upper limit is 24. The lower limit of the fourth class is 25, and the upper limit is 29.

Using these limits, we can calculate the lower class boundary for each class:

- For the first class, the lower class boundary is 9.5, which is halfway between 10 and 14.
- For the second class, the lower class boundary is 14.5, which is halfway between 15 and 19.
- For the third class, the lower class boundary is 19.5, which is halfway between 20 and 24.
- For the fourth class, the lower class boundary is 24.5, which is halfway between 25 and 29.

Therefore, the correct answer to the question is option B, Lower Class Boundary.