Final answer:
To find the probability of small company employees making more than the average 20 long-distance calls during peak times, one would use statistical models like the Poisson or normal distribution, depending on available data, to evaluate the tail end probabilities.
Step-by-step explanation:
To calculate the probability of employees at small companies making more than 20 long-distance phone calls during peak times, one would typically use a statistical model such as the Poisson or normal distribution. The exact approach would depend on the information given about the call patterns. However, since we know the average number of calls is 20, and we wish to find the probability of observing more than 20 calls, we'd generally look to the tail of the respective distribution representing occurrences above the mean.
In the practical application of these concepts, businesses might analyze such data to assess the adequacy of their current telecommunications plans or to make decisions on staffing a support service such as the one mentioned for SDSU's after hours hotline. The given information does not provide enough detail to carry out the exact calculation, but this is the general approach that would be taken in determining the probability of interest.