Finding the Fourth Proportional to 1,353.78, 1,866.78 and 881.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,353.78 : 1,866.78 = 881.13 : x
2. Step 2: Convert to fraction form
   1,353.78/1,866.78 = 881.13/x
3. Step 3: Cross multiply
   1,353.78x = 1,866.78 × 881.13
4. Step 4: Simplify right side
   1,353.78x = 1,644,875.86
5. Step 5: Solve for x
   x = 1,644,875.86/1,353.78
6. Step 6: Final answer
   x = 1,215.02