Finding the Third Proportional to 243,679.50 and 389,389.50

Step by Step Solution

1. Step 1: Write the proportion equation
   243,679.50 : 389,389.50 = 389,389.50 : x
2. Step 2: Convert to fraction form
   243,679.50/389,389.50 = 389,389.50/x
3. Step 3: Cross multiply
   243,679.50x = 389,389.50 × 389,389.50
4. Step 4: Simplify right side
   243,679.50x = 151,624,182,710.25
5. Step 5: Solve for x
   x = 151,624,182,710.25/243,679.50
6. Step 6: Final answer
   x = 622,227.90