Solution:

1) Display the ruler in 'Slide Master' view.

a) Move to 'Slide Master' view:

1] Select the 'View' menu and select 'Master'. (The Master submenu appears.)
2] Select 'Slide Master'. (The Slide Master slide appears.)

b) Select the 'View' menu and select 'Ruler'. (The ruler appears at the top of the screen.)
Ruler

2) Click in one of the placeholders. (The placeholder is selected, and the ruler displays moveable tabs.)
3) Select the desired ruler tab.
Select the ruler tab
4) Press and hold down the left mouse button. (A dotted line runs down the screen from the ruler tab.)
Dotted line
5) Drag the tab in the desired direction. (The dotted line moves, and the tab or indent is adjusted.)
6) Release the mouse button when the tab is in the desired location.
7) Repeat steps 3) through 6) for each tab or indent to adjust within the selected placeholder.
8) Click outside the placeholder to deselect it.
9) Repeat steps 3) through 8) for each placeholder in which to change tabs and indents.