Finding the Fourth Proportional to 1,356.64, 1,872.32 and 767.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.64 : 1,872.32 = 767.20 : x
2. Step 2: Convert to fraction form
   1,356.64/1,872.32 = 767.20/x
3. Step 3: Cross multiply
   1,356.64x = 1,872.32 × 767.20
4. Step 4: Simplify right side
   1,356.64x = 1,436,443.90
5. Step 5: Solve for x
   x = 1,436,443.90/1,356.64
6. Step 6: Final answer
   x = 1,058.82