Question

A number, x, rounded to 1 decimal place is 3.7
Write down the error interval for x.

Answer 1

Answer: (3.65, 3.74)

Explanation:

Now, when we round a number to a given decimal place, we need to look at the decimal to the left of the decimal place where we are rounding.

if it is 5 or more, we round up

if it is smaller than 5, we round down.

Then for example, if we want to round:

4.534

to the first decimal place, we need to look at the second decimal place.

we can see that it is a 2.

Then we round down, and get:

4.5

Now we know that, when rounding to the first decimal place, we have:

x = 3.7

Then the maximum value that x could have is:

x = 3.74 (because here we round down to 3.7)

and the minimum value that x could have is:

x = 3.65 (because here we round up to 3.7)

Then the error interval for x is:

(3.65, 3.74)