Question

Find a rational number with one decimal place that is between 17−−√
and 18−−√
.

Answer 1

To find a rational number with one decimal place that is between \(\sqrt{17}\) and \(\sqrt{18}\), we first need to approximate the square roots of these two numbers.

Calculating the square roots:

\[
\sqrt{17} \approx 4.123
\]

\[
\sqrt{18} \approx 4.243
\]

Now we need to find a rational number with one decimal place that lies between these two values. We can look for a decimal number in the range \(4.123\) to \(4.243\).

The possible candidates with one decimal place are \(4.1, 4.2\).

Both \(4.1\) and \(4.2\) are between \(4.123\) and \(4.243\).

Thus, a rational number with one decimal place that is between \(\sqrt{17}\) and \(\sqrt{18}\) is:

\[
\boxed{4.2}
\]