To save the presentation with a lower resolution, you must change the resolution using the Resolution box in the Slide Show tab.

For all purposes intended, this article will explain how to set the best image resolution for PowerPoint from both the Screen and Printer Resolution ...

You can change the size of a slide in your PowerPoint presentation through the "Design" menu on the Windows PC, Apple MacOS, and web-based apps.

Let’s begin on the notion that image resolution is the number of pixels in an image, measured in pixels per inch thus figuring out the optimal image resolution in PowerPoint is not so difficult ...