A Certain Glass Window Reduces the Intensity Level of the Sound

Multiple Choice

A certain glass window reduces the intensity level of the sound from 72 dB to 47 dB. By what factor is the acoustic power reduced by this glass window?

A) $1.5 \times 10 ^ { - 1 }$
B) $5.6 \times 10 ^ { - 2 }$
C) $3.2 \times 10 ^ { - 3 }$
D) $1.0 \times 10 ^ { - 1 }$
E) $2.2 \times 10 ^ { - 2 }$