Finding the Third Proportional to 13,380 and 20,428

Step by Step Solution

1. Step 1: Write the proportion equation
   13,380 : 20,428 = 20,428 : x
2. Step 2: Convert to fraction form
   13,380/20,428 = 20,428/x
3. Step 3: Cross multiply
   13,380x = 20,428 × 20,428
4. Step 4: Simplify right side
   13,380x = 417,303,184
5. Step 5: Solve for x
   x = 417,303,184/13,380
6. Step 6: Final answer
   x = 31,188.58