Finding the Third Proportional to 8,212 and 13,172

Step by Step Solution

1. Step 1: Write the proportion equation
   8,212 : 13,172 = 13,172 : x
2. Step 2: Convert to fraction form
   8,212/13,172 = 13,172/x
3. Step 3: Cross multiply
   8,212x = 13,172 × 13,172
4. Step 4: Simplify right side
   8,212x = 173,501,584
5. Step 5: Solve for x
   x = 173,501,584/8,212
6. Step 6: Final answer
   x = 21,127.81