What is the intensity of a 45 dB sound?

Question

I missed this chapter, and it honestly doesn't make sense to me.

Can someone walk me thought this?

The answer needs to be in W/m^2

Answer 1

You really need to know what the power reference level is, and the question does not give this information. However, it is usual for a reference of 10^-12 W/m^2 to be used for acoustics.

You can work out the rest.