Answer:
Able Cable
Explanation:
Mean Value of Samples
It's central tendency statistics measure that gives one representative value out of a complete dataset. It can be computed as the sum of the values by the number of values:

We need to evaluate the mean value of the three internet providers mentioned in the question.
For CityNet:

For Able Cable:

And for Tel-N-Net:

We can conclude Able Cable offers the fastest mean downloading internet speed