Inequality: 3.87 correct to 2 decimal places

[burgerandcheese]

Hello again guys how are you. If x = 3.87 is correct to 2 decimal places, then 3.865 ≤ x ≤ 3.875. But wouldn't that be wrong because if x is actually 3.875 then correct to 2 decimal places it would be x = 3.88. So shouldn't it be 3.865 ≤ x < 3.875?

 

[Dr.Peterson]

One reason for saying what they do is that there are different rules for rounding; not everyone, in every context, always rounds 5 up. That is a somewhat arbitrary convention. See here, for example.

By including both extremes, they allow for any convention, as well as the simpler absolute value form of the inequality.

 

[burgerandcheese]

One reason for saying what they do is that there are different rules for rounding; not everyone, in every context, always rounds 5 up. That is a somewhat arbitrary convention. See here, for example.

By including both extremes, they allow for any convention, as well as the simpler absolute value form of the inequality.

I see, wow! Something new I learnt today. Thank you Dr. Peterson