Question

is 5.172 a rational number? yes no

Explanation:

Step1: Recall rational number definition

A rational number is a number that can be expressed as $\frac{p}{q}$, where $p$ and $q$ are integers and $q
eq0$. Decimals that terminate or repeat are rational.

Step2: Analyze 5.172

5.172 is a terminating decimal. It can be written as $\frac{5172}{1000}$ (simplify if needed, but the key is it fits $\frac{p}{q}$ form with integers $p = 5172$, $q = 1000
eq0$).

Answer:

yes