Between which pair of rational numbers on a number line does √18 lie?

(1 point)

A. Between 4.2 and 4.3

B. Between 9 and 9.2

C. Between 8.9 and 9.1

D. Between 4.3 and 4.5

1 answer

To determine between which pair of rational numbers \(\sqrt{18}\) lies, we first need to approximate \(\sqrt{18}\).

We know that:

\[ \sqrt{16} = 4 \] \[ \sqrt{25} = 5 \]

Since \(16 < 18 < 25\), it follows that:

\[ 4 < \sqrt{18} < 5 \]

Next, we can refine this approximation. Since \(18\) is closer to \(16\) and \(25\), we can check \(4.2\) and \(4.3\):

Calculating \(4.2^2\):

\[ 4.2^2 = 17.64 \]

Calculating \(4.3^2\):

\[ 4.3^2 = 18.49 \]

Now we see that:

\[ 4.2^2 < 18 < 4.3^2 \]

This means that \(\sqrt{18}\) is between \(4.2\) and \(4.3\).

Thus, the answer is:

A. Between 4.2 and 4.3.