Finding the Third Proportional to 398,385 and 858,978

Step by Step Solution

1. Step 1: Write the proportion equation
   398,385 : 858,978 = 858,978 : x
2. Step 2: Convert to fraction form
   398,385/858,978 = 858,978/x
3. Step 3: Cross multiply
   398,385x = 858,978 × 858,978
4. Step 4: Simplify right side
   398,385x = 737,843,204,484
5. Step 5: Solve for x
   x = 737,843,204,484/398,385
6. Step 6: Final answer
   x = 1,852,085.81