Finding the Third Proportional to 551,138 and 780,078

Step by Step Solution

1. Step 1: Write the proportion equation
   551,138 : 780,078 = 780,078 : x
2. Step 2: Convert to fraction form
   551,138/780,078 = 780,078/x
3. Step 3: Cross multiply
   551,138x = 780,078 × 780,078
4. Step 4: Simplify right side
   551,138x = 608,521,686,084
5. Step 5: Solve for x
   x = 608,521,686,084/551,138
6. Step 6: Final answer
   x = 1,104,118.54