pop. In 1984 is less x

pop. In 1984 is equal 0

pop. In 1984 is greater y

TOTAL 1210

“all different” puts a 0 in the “equal to” row.

“The number of populations that were greater in 1984 than in 1980 was 20% greater than the number that were greater in 1980 than in 1984” means **y = 1.2x**

Obviously, x + 0 + y = 1210

x + 1.2x = 1210 [substitute value for y]

2.2x = 1210

x = 2010/2.2

x = 550

y = 1.2x

so, **y = 660 [greater population in 1984 than in 1980]**

Check:

Does x + y = 1210 ?

550 + 660 = 1210 ?

1210 = 1210 ?**yes**