Finding the Fourth Proportional to 1,392.78, 1,922.04 and 771.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.78 : 1,922.04 = 771.78 : x
2. Step 2: Convert to fraction form
   1,392.78/1,922.04 = 771.78/x
3. Step 3: Cross multiply
   1,392.78x = 1,922.04 × 771.78
4. Step 4: Simplify right side
   1,392.78x = 1,483,392.03
5. Step 5: Solve for x
   x = 1,483,392.03/1,392.78
6. Step 6: Final answer
   x = 1,065.06