Finding the Third Proportional to 243,729 and 392,080.50

Step by Step Solution

1. Step 1: Write the proportion equation
   243,729 : 392,080.50 = 392,080.50 : x
2. Step 2: Convert to fraction form
   243,729/392,080.50 = 392,080.50/x
3. Step 3: Cross multiply
   243,729x = 392,080.50 × 392,080.50
4. Step 4: Simplify right side
   243,729x = 153,727,118,480.25
5. Step 5: Solve for x
   x = 153,727,118,480.25/243,729
6. Step 6: Final answer
   x = 630,729.70