Finding the Fourth Proportional to 1,392.98, 1,922.31 and 771.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.98 : 1,922.31 = 771.98 : x
2. Step 2: Convert to fraction form
   1,392.98/1,922.31 = 771.98/x
3. Step 3: Cross multiply
   1,392.98x = 1,922.31 × 771.98
4. Step 4: Simplify right side
   1,392.98x = 1,483,984.87
5. Step 5: Solve for x
   x = 1,483,984.87/1,392.98
6. Step 6: Final answer
   x = 1,065.33