Finding the Fourth Proportional to 1,118.88, 1,540.89 and 869.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.88 : 1,540.89 = 869.76 : x
2. Step 2: Convert to fraction form
   1,118.88/1,540.89 = 869.76/x
3. Step 3: Cross multiply
   1,118.88x = 1,540.89 × 869.76
4. Step 4: Simplify right side
   1,118.88x = 1,340,204.49
5. Step 5: Solve for x
   x = 1,340,204.49/1,118.88
6. Step 6: Final answer
   x = 1,197.81