Finding the Third Proportional to 380,886 and 557,308

Step by Step Solution

1. Step 1: Write the proportion equation
   380,886 : 557,308 = 557,308 : x
2. Step 2: Convert to fraction form
   380,886/557,308 = 557,308/x
3. Step 3: Cross multiply
   380,886x = 557,308 × 557,308
4. Step 4: Simplify right side
   380,886x = 310,592,206,864
5. Step 5: Solve for x
   x = 310,592,206,864/380,886
6. Step 6: Final answer
   x = 815,446.63