Finding the Third Proportional to 257,499 and 389,002.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,499 : 389,002.50 = 389,002.50 : x
2. Step 2: Convert to fraction form
   257,499/389,002.50 = 389,002.50/x
3. Step 3: Cross multiply
   257,499x = 389,002.50 × 389,002.50
4. Step 4: Simplify right side
   257,499x = 151,322,945,006.25
5. Step 5: Solve for x
   x = 151,322,945,006.25/257,499
6. Step 6: Final answer
   x = 587,664.20