Finding the Third Proportional to 139,480 and 208,680

Step by Step Solution

1. Step 1: Write the proportion equation
   139,480 : 208,680 = 208,680 : x
2. Step 2: Convert to fraction form
   139,480/208,680 = 208,680/x
3. Step 3: Cross multiply
   139,480x = 208,680 × 208,680
4. Step 4: Simplify right side
   139,480x = 43,547,342,400
5. Step 5: Solve for x
   x = 43,547,342,400/139,480
6. Step 6: Final answer
   x = 312,212.09