Finding the Fourth Proportional to 1,128.24, 1,557.90 and 779.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.24 : 1,557.90 = 779.94 : x
2. Step 2: Convert to fraction form
   1,128.24/1,557.90 = 779.94/x
3. Step 3: Cross multiply
   1,128.24x = 1,557.90 × 779.94
4. Step 4: Simplify right side
   1,128.24x = 1,215,068.53
5. Step 5: Solve for x
   x = 1,215,068.53/1,128.24
6. Step 6: Final answer
   x = 1,076.96