Rather than create a new slide from scratch, you want to instead make a copy of Slide $11$ and then modify its content. To do this you would:

Select Slide $11$ and click the Copy button on the Home Ribbon.

Select Slide $11,$ click the New Slide button arrow and click Duplicate Selected Slides.

Select Slide $11,$ click the Insert button arrow and click Duplicate Selected Slides.

Select Slide $11$ and click the Insert button on the Home Ribbon.