Question

The depth, d , of a lake is 57 m, rounded to the nearest integer. Write the error interval for d in the form a ≤ d < b .

Answer 1

Given:

The depth, d , of a lake is 57 m, rounded to the nearest integer.

To find:

The error interval for d in the form a ≤ d < b.

Solution:

The depth, d , of a lake is 57 m, rounded to the nearest integer.

If the depths of the lake is 56.5m or greater than this up to 57 m, then the depth, d , of a lake is 57 m, rounded to the nearest integer.

`56.5\leq d\leq 57` ...(i)

If the depths of the lake is 57m or greater than this up to 57.5 m but not 57.5 m, then the depth, d , of a lake is 57 m, rounded to the nearest integer.

`57\leq d<57.5` ...(ii)

Using (i) and (ii), we get

`56.5\leq d<57.5`

Therefore, the error interval for d is
`56.5\leq d<57.5`.