A fishery has a large tank for raising fingerling perch. 500 perch with a mean length
of 1.2 inches were placed in the tank. The fishery biologists have determined that
the perch need to be fingerlings before they can be release in the wild. One moth
later they remove 20 fish and find that the average length is 4.5 inches. The
determine that all of the perch are fingerling size and ready to be released.
What is the sample mean?
A) 1.2
B) 500
C) 4.5