Finding the Third Proportional to 257,538 and 378,862.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,538 : 378,862.50 = 378,862.50 : x
2. Step 2: Convert to fraction form
   257,538/378,862.50 = 378,862.50/x
3. Step 3: Cross multiply
   257,538x = 378,862.50 × 378,862.50
4. Step 4: Simplify right side
   257,538x = 143,536,793,906.25
5. Step 5: Solve for x
   x = 143,536,793,906.25/257,538
6. Step 6: Final answer
   x = 557,342.19