The mid value of a class interval is the average of the lower and upper limits of that interval.
In other words, it's the midpoint of the range defined by the class interval. To calculate it, you sum the lower and upper limits and then divide by two.
Here's a more detailed explanation:
Calculating the Mid Value
To determine the mid-value:
- Identify the lower limit (L) of the interval.
- Identify the upper limit (U) of the interval.
- Apply the formula: Mid-value = (L + U) / 2
Example
Let's say we have a class interval of 10-20.
- Lower limit (L) = 10
- Upper limit (U) = 20
Mid-value = (10 + 20) / 2 = 30 / 2 = 15
Therefore, the mid-value of the class interval 10-20 is 15.
Significance of the Mid Value
The mid-value is often used as a representative value for all the data points within that class interval when calculating statistics like the mean from grouped data. It's a simplification that allows for calculations when the individual data points are not known, only the frequency within each interval.
