Finding the Third Proportional to 13,386 and 20,428.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,386 : 20,428.50 = 20,428.50 : x
2. Step 2: Convert to fraction form
   13,386/20,428.50 = 20,428.50/x
3. Step 3: Cross multiply
   13,386x = 20,428.50 × 20,428.50
4. Step 4: Simplify right side
   13,386x = 417,323,612.25
5. Step 5: Solve for x
   x = 417,323,612.25/13,386
6. Step 6: Final answer
   x = 31,176.13