To determine the class midpoint of the highest class in a frequency distribution, we need to follow these steps:
1. Identify the Class Interval: The highest class in the given data is the class with the age range 60 up to 70.
2. Find the Lower and Upper Bounds of the Class Interval:
- The lower bound of this class interval is 60.
- The upper bound of this class interval is 70.
3. Calculate the Midpoint: The midpoint of a class interval is found by averaging the lower and upper bounds. This is done by adding the lower and upper bounds and then dividing by 2.
Following this procedure with the identified class interval (60 to 70):
[tex]\[
\text{Midpoint} = \frac{\text{Lower Bound} + \text{Upper Bound}}{2}
\][/tex]
Substituting the values:
[tex]\[
\text{Midpoint} = \frac{60 + 70}{2}
\][/tex]
[tex]\[
\text{Midpoint} = \frac{130}{2}
\][/tex]
[tex]\[
\text{Midpoint} = 65.0
\][/tex]
Therefore, the class midpoint of the highest class is:
[tex]\[
65
\][/tex]
So, the correct answer is:
[tex]\[
\boxed{65}
\][/tex]
