Question

Tia rounds a number, x , to 3 sf. The result is 9.73. Write the error interval for x in the form a ≤ x < b .

Answer 1

Answer: 9.725  ≤ x ≤ 9.734

Step-by-step explanation:

We know that 9.73 is rounded, then we need to look at the next digit after the last one of 9.73, this would be the third digit after the decimal point.

We know that if this digit is smaller than 5, then we round down.

Then the largest number that can be rounded down to 9.73 is:

9.734

Now we want to find the smallest number that can be rounded up to 9.73

We know that if the next digit is 5 or bigger, then we round up.

Then the number 9.725 is rounded up to 9.73

And this is the smallest number that can be rounded up to 9.73

Then the error interval is:

9.725  ≤ x ≤ 9.734