Final answer:
The question relates to using statistical methods to calculate probabilities and understand demographic data. It involves working with normal distributions, calculating probabilities for certain age ranges, and examining historical increases in the senior citizen population.
Step-by-step explanation:
The question appears to pertain to probability and statistics, specifically calculating probabilities and understanding demographic shifts in populations. An example provided about calculating probabilities is determining the probability that a randomly selected smartphone user is within a certain age range, assuming a normal distribution of ages. Another aspect of the question deals with the historical increase in the senior citizen population and its implications.
In addressing such questions, we would use statistical techniques to calculate probabilities and interpret demographic data. For example, to calculate the probability that a randomly selected person is at most 50.8 years old given a population with a known mean and standard deviation, we would use the normal distribution and z-scores.