Finding the Fourth Proportional to 1,380.11, 1,902.76 and 881.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.11 : 1,902.76 = 881.89 : x
2. Step 2: Convert to fraction form
   1,380.11/1,902.76 = 881.89/x
3. Step 3: Cross multiply
   1,380.11x = 1,902.76 × 881.89
4. Step 4: Simplify right side
   1,380.11x = 1,678,018.05
5. Step 5: Solve for x
   x = 1,678,018.05/1,380.11
6. Step 6: Final answer
   x = 1,215.86