You correctly found the mean age of the data set for the 6 p.m. time in the mall. However, the mean age of the data set for the 1 p.m. time is about 43, so there will probably be more people in the mall at that time who might be interested in retirement planning. Also, the mean or average could be misleading. There could be many people who are old and many who are young, with an average age around 26, for example, without anyone actually being around the age of 26.