Final answer:
The statement about customers thinking they have waited 3-4 minutes when they have actually waited 30-40 seconds is false according to the provided data, which describes average intervals of customer arrivals but does not reference customers' perception of wait times.
Step-by-step explanation:
The direct answer to the question about customers' perception of time while waiting is False, as based on the given scenarios, each customer arrives on average every two minutes, and it takes six minutes on average for three customers to arrive. There is no mention of the 30-40 second perception leading to a 3-4 minute psychological wait time in the reference information provided.
In detail, if one customer arrives every two minutes ⟨em>on average⟨/em>, then the answer to part (a) is that two minutes elapse between two successive arrivals. For part (b), considering the arrival rate is consistent, it would sequentially take two minutes for the first customer to arrive, another two for the second, and another two for the third when the store opens, totaling six minutes on average for three customers to arrive.
In business practice, customers' perception of wait times can indeed be skewed, where brief waits could feel much longer than they actually are. However, the question's assertion isn't substantiated by the given data, which pertains specifically to the calculation of average times between customer arrivals and not customers' psychological perceptions.