Finding the Third Proportional to 414,315 and 639,788.63

Step by Step Solution

1. Step 1: Write the proportion equation
   414,315 : 639,788.63 = 639,788.63 : x
2. Step 2: Convert to fraction form
   414,315/639,788.63 = 639,788.63/x
3. Step 3: Cross multiply
   414,315x = 639,788.63 × 639,788.63
4. Step 4: Simplify right side
   414,315x = 409,329,484,679.39
5. Step 5: Solve for x
   x = 409,329,484,679.39/414,315
6. Step 6: Final answer
   x = 987,966.85