Step 1. Understand the terms of the comparison. The comparison that Singer is making here should be obvious - he's likening a drowning child to a starving populace. Furthermore, just as we should rescue a drowning child from a shallow pond if it poses no real physical danger to us, so developed nations should rescue the starving population of an undeveloped country if it poses no significant financial hazards to them.
Formatted as a Miller Analogy (the four-termed comparison discussed in the video lecture for Unit 6), the analogy would look like this:
A child drowning in a shallow pond : a passerby :: a starving populace in an undeveloped nation : the developed nations of the world
Step 2. Frame the comparison as an argument (reasoning by analogy): As you can see, this comparison suggests an argument:
P1: Just as an individual should not ignore the plight of a child drowning in shallow waters, C: So the developed nations of the world should not ignore the plight of a starving population in a small, undeveloped nation.
 PHIL 110 Critical Thinking - SPS CUNY 1

Step 3. Your turn: use ONE of the following comparisons to compose an analogical argument:
• A basketball team compared to a military unit; or
• A marriage compared to a house; or
• Global warming compared to the sinking of the Titanic; or
• Composing music (any genre - hip hop, jazz, soul, classical, folk, etc.) compared to painting a picture; or
• The cost of a college education compared to the cost of health care.