Let ${x_1},{x_2},{x_3},{x_4}$ be in a geometric progression. If 2,7,9,5 are subtracted respectively from ${x_1},{x_2},{x_3},{x_4}$, then the resulting numbers are in an arithmetic progression. Then the value of $\frac{1}{{24}}\left( {{x_1}{x_2}{x_3}{x_4}} \right)$ is:
