Finding the Third Proportional to 139,478 and 286,372

Step by Step Solution

1. Step 1: Write the proportion equation
   139,478 : 286,372 = 286,372 : x
2. Step 2: Convert to fraction form
   139,478/286,372 = 286,372/x
3. Step 3: Cross multiply
   139,478x = 286,372 × 286,372
4. Step 4: Simplify right side
   139,478x = 82,008,922,384
5. Step 5: Solve for x
   x = 82,008,922,384/139,478
6. Step 6: Final answer
   x = 587,970.31