Finding the Fourth Proportional to 1,392.31, 1,921.43 and 762.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.31 : 1,921.43 = 762.89 : x
2. Step 2: Convert to fraction form
   1,392.31/1,921.43 = 762.89/x
3. Step 3: Cross multiply
   1,392.31x = 1,921.43 × 762.89
4. Step 4: Simplify right side
   1,392.31x = 1,465,843.11
5. Step 5: Solve for x
   x = 1,465,843.11/1,392.31
6. Step 6: Final answer
   x = 1,052.81