Finding the Third Proportional to 128,815.50 and 283,321.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,815.50 : 283,321.50 = 283,321.50 : x
2. Step 2: Convert to fraction form
   128,815.50/283,321.50 = 283,321.50/x
3. Step 3: Cross multiply
   128,815.50x = 283,321.50 × 283,321.50
4. Step 4: Simplify right side
   128,815.50x = 80,271,072,362.25
5. Step 5: Solve for x
   x = 80,271,072,362.25/128,815.50
6. Step 6: Final answer
   x = 623,147.62