Finding the Third Proportional to 139,420 and 299,078

Step by Step Solution

1. Step 1: Write the proportion equation
   139,420 : 299,078 = 299,078 : x
2. Step 2: Convert to fraction form
   139,420/299,078 = 299,078/x
3. Step 3: Cross multiply
   139,420x = 299,078 × 299,078
4. Step 4: Simplify right side
   139,420x = 89,447,650,084
5. Step 5: Solve for x
   x = 89,447,650,084/139,420
6. Step 6: Final answer
   x = 641,569.72