Finding the Third Proportional to 391,978.50 and 858,654

Step by Step Solution

1. Step 1: Write the proportion equation
   391,978.50 : 858,654 = 858,654 : x
2. Step 2: Convert to fraction form
   391,978.50/858,654 = 858,654/x
3. Step 3: Cross multiply
   391,978.50x = 858,654 × 858,654
4. Step 4: Simplify right side
   391,978.50x = 737,286,691,716
5. Step 5: Solve for x
   x = 737,286,691,716/391,978.50
6. Step 6: Final answer
   x = 1,880,936.56