Finding the Third Proportional to 686,640 and 1,005,380

Step by Step Solution

1. Step 1: Write the proportion equation
   686,640 : 1,005,380 = 1,005,380 : x
2. Step 2: Convert to fraction form
   686,640/1,005,380 = 1,005,380/x
3. Step 3: Cross multiply
   686,640x = 1,005,380 × 1,005,380
4. Step 4: Simplify right side
   686,640x = 1,010,788,944,400
5. Step 5: Solve for x
   x = 1,010,788,944,400/686,640
6. Step 6: Final answer
   x = 1,472,079.90