In Exercises 19-24, write the next three terms of the geometric sequence. \( \mathrm{W}: \)
(See Examples 2 and 3.)
19. \( 5,20,80,320, \ldots \)
20. \( -3,12,-48,192, \ldots \)
21. \( 81,-27,9,-3, \ldots \)
22. \( -375,-75,-15,-3, \ldots \)
23. \( 32,82, \frac{1}{2}, \ldots \)
24. \( \frac{16}{9}, \frac{8}{3}, 4,6, \ldots \)