Finding the Third Proportional to 287,826 and 431,772.75

Step by Step Solution

1. Step 1: Write the proportion equation
   287,826 : 431,772.75 = 431,772.75 : x
2. Step 2: Convert to fraction form
   287,826/431,772.75 = 431,772.75/x
3. Step 3: Cross multiply
   287,826x = 431,772.75 × 431,772.75
4. Step 4: Simplify right side
   287,826x = 186,427,707,642.56
5. Step 5: Solve for x
   x = 186,427,707,642.56/287,826
6. Step 6: Final answer
   x = 647,709.75