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GB-38-02-001 · Truncation intervals

A positive number x is truncated to 1 decimal place, giving 80.6. Write the error interval for x.

Error Intervals: Truncating Booklet p. 63
Method
1) List possible values before truncation
2) Identify the included lower bound and excluded upper bound
3) Write the error interval
Worked Example (GB-38-02-001)
1)
List possible numbers before truncation: 80.6, 80.61, 80.65, 80.69980.6,\ 80.61,\ 80.65,\ 80.699. Cutting off after the first decimal place gives 80.680.6 in every case.
2)
The smallest possible value is 80.680.6, which is included. The next tenth is 80.780.7, which would truncate to a different value and is excluded.
3)
Write the error interval: 80.6≤x<80.780.6\le x<80.7.
Ans = 80.6≤x<80.780.6\le x<80.7