Finding the Third Proportional to 287,665.88 and 431,498.63

Step by Step Solution

1. Step 1: Write the proportion equation
   287,665.88 : 431,498.63 = 431,498.63 : x
2. Step 2: Convert to fraction form
   287,665.88/431,498.63 = 431,498.63/x
3. Step 3: Cross multiply
   287,665.88x = 431,498.63 × 431,498.63
4. Step 4: Simplify right side
   287,665.88x = 186,191,063,376.89
5. Step 5: Solve for x
   x = 186,191,063,376.89/287,665.88
6. Step 6: Final answer
   x = 647,247.66