Finding the Fourth Proportional to 1,379.30, 1,902.56 and 881.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.30 : 1,902.56 = 881.78 : x
2. Step 2: Convert to fraction form
   1,379.30/1,902.56 = 881.78/x
3. Step 3: Cross multiply
   1,379.30x = 1,902.56 × 881.78
4. Step 4: Simplify right side
   1,379.30x = 1,677,625.44
5. Step 5: Solve for x
   x = 1,677,625.44/1,379.30
6. Step 6: Final answer
   x = 1,216.29