Finding the Fourth Proportional to 1,050.78, 1,573.94 and 854.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,050.78 : 1,573.94 = 854.88 : x
2. Step 2: Convert to fraction form
   1,050.78/1,573.94 = 854.88/x
3. Step 3: Cross multiply
   1,050.78x = 1,573.94 × 854.88
4. Step 4: Simplify right side
   1,050.78x = 1,345,529.83
5. Step 5: Solve for x
   x = 1,345,529.83/1,050.78
6. Step 6: Final answer
   x = 1,280.51