To find an irrational number between \( \sqrt{14} \) and \( \sqrt{18} \), we first calculate the approximate values of these square roots.
Calculating \( \sqrt{14} \): \[ \sqrt{14} \approx 3.74 \]
Calculating \( \sqrt{18} \): \[ \sqrt{18} \approx 4.24 \]
Now, we need to find an irrational number that lies between these two values. One such number could be \( \sqrt{15} \).
Calculating \( \sqrt{15} \): \[ \sqrt{15} \approx 3.87 \]
Since \( 3.74 < \sqrt{15} < 4.24 \), \( \sqrt{15} \) is indeed between \( \sqrt{14} \) and \( \sqrt{18} \).
Thus, an irrational number between \( \sqrt{14} \) and \( \sqrt{18} \) is: \[ \sqrt{15} \]