Finding the Third Proportional to 139,458 and 287,172

Step by Step Solution

1. Step 1: Write the proportion equation
   139,458 : 287,172 = 287,172 : x
2. Step 2: Convert to fraction form
   139,458/287,172 = 287,172/x
3. Step 3: Cross multiply
   139,458x = 287,172 × 287,172
4. Step 4: Simplify right side
   139,458x = 82,467,757,584
5. Step 5: Solve for x
   x = 82,467,757,584/139,458
6. Step 6: Final answer
   x = 591,344.76