Question

Which is a better approximation of the square root of20, 4.5 or 4.47

Answer 1

`√(20) = 4.472135955`

≈ 4.47 when rounded to the nearest hundredth OR

≈ 4.5 when rounded to the nearest tenth

→ 4.47 is a better approximation since it contains a digit in the hundredth place rather than none at all.

Answer 2

4.47

Explanation:

Given :
`√(20)`

To Find : Which is a better approximation

Solution:

20 lies between two perfect squares i.e. 16 and 25

Square root of 16 = 4

Square root of 25 = 5

So, Square root of 20 must lie between 4 and 5

Using calculator

The
`√(20)=4.47`

Hence a better approximation of the square root of 20 is 4.47.