Finding the Third Proportional to 139,830 and 209,760

Step by Step Solution

1. Step 1: Write the proportion equation
   139,830 : 209,760 = 209,760 : x
2. Step 2: Convert to fraction form
   139,830/209,760 = 209,760/x
3. Step 3: Cross multiply
   139,830x = 209,760 × 209,760
4. Step 4: Simplify right side
   139,830x = 43,999,257,600
5. Step 5: Solve for x
   x = 43,999,257,600/139,830
6. Step 6: Final answer
   x = 314,662.50