What is the smallest and largest whole numbers that round off to 600000 to the nearest hundred thousands?

Answer 1

Smallest: 550000

Largest: 650000

Some statistically naive people will argue that 650000 would be rounded up to 700000. What they do not realise is that the process of always rounding up 5 introduces a bias.

This is because, if you do that, you

do not round for 0.

round down for 1, 2, 3 and 4

round up for 5, 6, 7, 8 and 9

So there is 10% more rounding up than down (5/10 up against 4/10 down). That is introducing an upward bias. The recommended solution is to round the other digits as before but to round 5 so that the last "surviving" digit is even.