Finding the Fourth Proportional to 1,392.18, 1,921.24 and 762.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.18 : 1,921.24 = 762.72 : x
2. Step 2: Convert to fraction form
   1,392.18/1,921.24 = 762.72/x
3. Step 3: Cross multiply
   1,392.18x = 1,921.24 × 762.72
4. Step 4: Simplify right side
   1,392.18x = 1,465,368.17
5. Step 5: Solve for x
   x = 1,465,368.17/1,392.18
6. Step 6: Final answer
   x = 1,052.57