Finding the Fourth Proportional to 1,129.59, 1,558.41 and 687.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,129.59 : 1,558.41 = 687.33 : x
2. Step 2: Convert to fraction form
   1,129.59/1,558.41 = 687.33/x
3. Step 3: Cross multiply
   1,129.59x = 1,558.41 × 687.33
4. Step 4: Simplify right side
   1,129.59x = 1,071,141.95
5. Step 5: Solve for x
   x = 1,071,141.95/1,129.59
6. Step 6: Final answer
   x = 948.26