Finding the Third Proportional to 189,408 and 420,856.50

Step by Step Solution

1. Step 1: Write the proportion equation
   189,408 : 420,856.50 = 420,856.50 : x
2. Step 2: Convert to fraction form
   189,408/420,856.50 = 420,856.50/x
3. Step 3: Cross multiply
   189,408x = 420,856.50 × 420,856.50
4. Step 4: Simplify right side
   189,408x = 177,120,193,592.25
5. Step 5: Solve for x
   x = 177,120,193,592.25/189,408
6. Step 6: Final answer
   x = 935,125.20