What sets of numbers does 1.18 belong?

Answer 1

To any set that contains it!

It belongs to {1.18},

or {45, sqrt(2), pi, 1.18, -3/7},

or all numbers between -2 and 453,

or improper fractions (1.18 = 19/50],

or rational numbers,

or real numbers,

or complex numbers,

etc.