The number 3.192 is not an irrational number; it is a rational number. Rational numbers are numbers that can be expressed as a fraction \( \frac{a}{b} \), where \( a \) and \( b \) are integers and \( b \) is not zero. Since 3.192 can be expressed as \( \frac{3192}{1000} \) or in other fractional forms, it is classified as a rational number.
In contrast, irrational numbers cannot be expressed as simple fractions and have non-repeating, non-terminating decimal expansions, such as \(\sqrt{2}\) or \(\pi\).