Answer :
Population density is = population per unit area
i.e 20/5 m^2
= 4 mice per m^2
i.e 20/5 m^2
= 4 mice per m^2
you have to divide the total mice (20) by the area of the field (5)
20/ 5 is 4
4 mice per m^2
20/ 5 is 4
4 mice per m^2