The following data are monthly rents (in dollars) of studio and one-bedroom apartments in harrisburg, pennsylvania, in 2007, obtained from a random sample of such apartments advertised at rent,com in july 2007:
500, 549, 569, 575, 585, 600, 630, 680, 705, 790

The mean of these ten rent prices is $618.3, and the standard deviation is $85.3.
Describe what the population mean mu means in this context.