Finding the Third Proportional to 189,378 and 405,355.50

Step by Step Solution

1. Step 1: Write the proportion equation
   189,378 : 405,355.50 = 405,355.50 : x
2. Step 2: Convert to fraction form
   189,378/405,355.50 = 405,355.50/x
3. Step 3: Cross multiply
   189,378x = 405,355.50 × 405,355.50
4. Step 4: Simplify right side
   189,378x = 164,313,081,380.25
5. Step 5: Solve for x
   x = 164,313,081,380.25/189,378
6. Step 6: Final answer
   x = 867,646.09