Finding the Third Proportional to 139,603.50 and 299,436.75

Step by Step Solution

1. Step 1: Write the proportion equation
   139,603.50 : 299,436.75 = 299,436.75 : x
2. Step 2: Convert to fraction form
   139,603.50/299,436.75 = 299,436.75/x
3. Step 3: Cross multiply
   139,603.50x = 299,436.75 × 299,436.75
4. Step 4: Simplify right side
   139,603.50x = 89,662,367,250.56
5. Step 5: Solve for x
   x = 89,662,367,250.56/139,603.50
6. Step 6: Final answer
   x = 642,264.47