Answer :
The upper class limit of the third class, based on the provided class boundaries of a frequency distribution, is 79.5.
The upper class limit of the third class can be determined by identifying the class boundaries from the given data. In this situation, we have class boundaries presented in the histogram as 50 to less than 60 (1st class), 60 to less than 70 (2nd class), and 70 to less than 80 (3rd class). Therefore, the upper class limit for the third class is 79.5, which is the highest value that falls into the 70 to less than 80 range.