We must multiply both numerator and denominator by a number such that the new denominator is 100.
So, we want to perform the following transformation:
[tex] \dfrac{16}{2000} \to \dfrac{16x}{2000x} = \dfrac{16x}{100} [/tex]
So, in particular, we want [tex] 2000x = 100 [/tex], which yields
[tex] x = \dfrac{100}{2000} = \dfrac{1}{20} [/tex]
We also have to multiply the numerator by that quantity, obtaining
[tex] 16 \cdot \dfrac{1}{20} = \dfrac{16}{20} = \dfrac{4}{5} = 0.8 [/tex]
So, the answer is
[tex] \dfrac{16}{2000} =\dfrac{16\cdot\frac{1}{20}}{2000\cdot\frac{1}{20}} =\dfrac{0.8}{100} [/tex]
Which means that 16 over 2000 is 0.8%
