Quantitative relationship between entropy and number of microstates

A gaseous system undergoes a change in temperature and volume. What is the entropy change for a particle in this system if the final number of microstates is 0.408 times that of the initial number of microstates?

S=klnW
k=1.38x10^-23 j/K(particles)


Please explain if possible! Thank you!

S = k ln(Omega)
on Boltzmann's tombstone!!!


Sinitial = k lnw
S final = k ln (w*0.408)


delta S = k ( ln(w*0.408) - lnw )

by quality of logs.....

delta S = k ln(0.408)