Image logo should maintain a size relative to the device screen size

I have a basic Layout question.

When using the layout tab (rather than the coding tab) in my main.xml, I am trying to create a home screen for when my app opens.

There is going to be the logo at the top center, then 3 simple buttons below, all centered.

How do I go about formatting the Logo so it maintains a size relative to the person's screen size, and stays in the center?

I don't want to write sloppy code to where my program looks fine (UI wise) on my screen and is poorly formatted on other's screens.

Al开发者_开发知识库so, is there good documentation explaining all of the Property values in the layout view?

You can use different scale types for you images (see https://developer.android.com/reference/android/widget/ImageView.ScaleType.html).
View attributes can be find at https://developer.android.com/reference/android/view/View.html.