Finding the Third Proportional to 1,405,878 and 2,178,729

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405,878 : 2,178,729 = 2,178,729 : x
2. Step 2: Convert to fraction form
   1,405,878/2,178,729 = 2,178,729/x
3. Step 3: Cross multiply
   1,405,878x = 2,178,729 × 2,178,729
4. Step 4: Simplify right side
   1,405,878x = 4,746,860,055,441
5. Step 5: Solve for x
   x = 4,746,860,055,441/1,405,878
6. Step 6: Final answer
   x = 3,376,438.11