Finding the Third Proportional to 139,442 and 287,140

Step by Step Solution

1. Step 1: Write the proportion equation
   139,442 : 287,140 = 287,140 : x
2. Step 2: Convert to fraction form
   139,442/287,140 = 287,140/x
3. Step 3: Cross multiply
   139,442x = 287,140 × 287,140
4. Step 4: Simplify right side
   139,442x = 82,449,379,600
5. Step 5: Solve for x
   x = 82,449,379,600/139,442
6. Step 6: Final answer
   x = 591,280.82