The question asks for the error interval of $x$, where $x$ is a number rounded to 1 decimal place and given as 12.3.

To find the error interval for a number rounded to 1 decimal place, the margin of error is $\pm 0.05$, which is half of 0.1 (the next decimal place).

The error interval for $x$:

• Lower bound: $12.3 - 0.05 = 12.25$
• Upper bound: $12.3 + 0.05 = 12.35$

Thus, the error interval for $x$ is: $12.25 \leq x < 12.35$

This is the range in which $x$ lies, with values from 12.25 up to, but not including, 12.35.

Do you want further clarification or more details?

Here are 5 related questions:

1. How do you calculate an error interval for a number rounded to 2 decimal places?
2. What is the difference between absolute and relative error?
3. How would you express the error interval in terms of inequalities?
4. How does rounding affect the precision of a number?
5. How do you determine the bounds for error intervals in general?

Tip: When rounding to any decimal place, the error interval is determined by half of the next decimal place value.