Finding the Third Proportional to 8,820 and 13,621.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,820 : 13,621.50 = 13,621.50 : x
2. Step 2: Convert to fraction form
   8,820/13,621.50 = 13,621.50/x
3. Step 3: Cross multiply
   8,820x = 13,621.50 × 13,621.50
4. Step 4: Simplify right side
   8,820x = 185,545,262.25
5. Step 5: Solve for x
   x = 185,545,262.25/8,820
6. Step 6: Final answer
   x = 21,036.88