Explanation:

To understand why the correct answer is option 'A' (upper limit), let's first define what each option represents in the context of a class interval.

- Upper limit: The upper limit of a class interval represents the highest value that falls within that interval. In this case, the class interval is 70-80, so the upper limit is 80.

- Frequency: Frequency refers to the number of times an event or value occurs. It is not relevant to determining the upper limit in this context.

- Range: The range is the difference between the maximum and minimum values in a data set. It does not directly relate to the upper limit of a specific class interval.

- Lower limit: The lower limit of a class interval represents the lowest value that falls within that interval. It is not relevant to determining the upper limit in this context.

Now, let's further explain why the correct answer is the upper limit:

- In the given class interval 70-80, the numbers 70 and 80 represent the lower and upper limits of the interval, respectively.
- The lower limit (70) defines the starting point of the interval, while the upper limit (80) defines the ending point.
- The class interval includes all values from 70 to 80, including both limits.
- The upper limit is specifically mentioned in the question as the value in the class interval that needs to be determined.

Therefore, based on the definition of the upper limit and the given information in the question, the correct answer is option 'A' (upper limit).

A ) upper limit will be the answer because lower limit is 70 , range is 70+80/2=75 , frequency will be the no. of observations that occur in a particular predefined interval so therefore upper limit will be 80