Final answer:
To calculate the average value for the given experimentally determined number, add up all the numbers and divide the sum by the total count of numbers. In this case, the average value for the number 2.78 is 2.78.
Step-by-step explanation:
To calculate the average value, also known as the mean, for the experimentally determined numbers, you need to add up all the numbers and divide the sum by the total count of numbers.
In this case, you only have one number, which is 2.78.
Mean = (2.78) / 1 = 2.78
Therefore, the average value for the experimentally determined number 2.78 is 2.78.