Final answer:
The mode of the given set of data is the number that appears most often, which is 95.
Step-by-step explanation:
The mode of a set of data is the number that appears most frequently. In the provided data set (78, 79, 80, 80, 89, 89, 92, 93, 94, 95, 95, 95), the number 95 appears the most frequently, three times, making it the mode.
To express the mode as an integer, the answer is simply 95.