Final answer:
Marjorie Joyner did invent the Permanent Wave Machine in 1928, but not under Madam C. J. Walker's company as she had passed away in 1919. The statement is false.
Step-by-step explanation:
The assertion that Marjorie Joyner invented the Permanent Wave Machine under the company owned by Madam C. J. Walker is false. In fact, it was indeed Marjorie Joyner who patented this device in 1928, but it was not under Madam C. J. Walker's company. Marjorie Joyner was associated with the Madam C. J. Walker Manufacturing Company and made significant contributions to the world of beauty through her innovations, but the founding figure of the company, Madam C. J. Walker, had already passed away in 1919. The permanent wave machine was Joyner's own creation.