Modulus of a Complex Number

Consider the complex number represented in the form of an ordered pair:

$$ z = 3 + 4i $$

where $i$ is the imaginary unit, defined by the property that $i^2 = -1$. Calculate the modulus of the complex number $z$. The modulus of a complex number $a + bi$ is given by the formula:

$$ |z| = ext{sqrt}(a^2 + b^2) $$

What is the value of the modulus of $z$? Enter your answer as a decimal number or a simplified fraction in the grid below.