Finding the Third Proportional to 257,391 and 387,976.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,391 : 387,976.50 = 387,976.50 : x
2. Step 2: Convert to fraction form
   257,391/387,976.50 = 387,976.50/x
3. Step 3: Cross multiply
   257,391x = 387,976.50 × 387,976.50
4. Step 4: Simplify right side
   257,391x = 150,525,764,552.25
5. Step 5: Solve for x
   x = 150,525,764,552.25/257,391
6. Step 6: Final answer
   x = 584,813.63