Finding the Modulus of a Complex Number

Consider the complex number represented in the form $a + bi$, where $a$ and $b$ are real numbers. If $z = 3 + 4i$, find the modulus of the complex number $z$. The modulus of a complex number $z = a + bi$ is given by the formula $|z| = \sqrt{a^2 + b^2}$. Please express your answer as a decimal.