Finding the Third Proportional to 257,411.50 and 389,442.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,411.50 : 389,442.50 = 389,442.50 : x
2. Step 2: Convert to fraction form
   257,411.50/389,442.50 = 389,442.50/x
3. Step 3: Cross multiply
   257,411.50x = 389,442.50 × 389,442.50
4. Step 4: Simplify right side
   257,411.50x = 151,665,460,806.25
5. Step 5: Solve for x
   x = 151,665,460,806.25/257,411.50
6. Step 6: Final answer
   x = 589,194.58