Answer:
The population of Queens increased by 16,075.
The population of Brooklyn increased by 11,870 more than that, then the population of Brooklyn increased by:
16,075 + 11,870 = 27,945
a) The total combined population increase is (when we round the addens)
I will round in the thousands place.
To do it, we must look at the hundreds place, if the decimal is 5 or larger, we round up.
If the decimal is smaller than 5, we round down.
16,074 ≈ 16,000
27,945 ≈ 28,000
16,000 + 28,000 = 44,000
b) Now using the actual numbers:
16,075 + 27,945 = 44,020.
c) now let's compare our two results:
Let's see the difference between them
a = 44,000
b = 44,020
a - b = 44,000 - 44,020 = -20.
This means that our estimated from (a) is 20 units smaller than the actual number.
But this is insignificant compared with the 44,020.
Why?
we can calculate the relative error as:
100%*(estimate value - real value)/(real value)
100%*(-20/44,020) = -0.05%
So the error is on the -0.05%, which is despreciable.
From this, we can conclude that the estimation in (a) is a really good estimation.