Finding the Third Proportional to 243,185.10 and 388,491.98

Step by Step Solution

1. Step 1: Write the proportion equation
   243,185.10 : 388,491.98 = 388,491.98 : x
2. Step 2: Convert to fraction form
   243,185.10/388,491.98 = 388,491.98/x
3. Step 3: Cross multiply
   243,185.10x = 388,491.98 × 388,491.98
4. Step 4: Simplify right side
   243,185.10x = 150,926,017,370.98
5. Step 5: Solve for x
   x = 150,926,017,370.98/243,185.10
6. Step 6: Final answer
   x = 620,621.98