Finding the Fourth Proportional to 1,378.71, 1,902.84 and 881.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.71 : 1,902.84 = 881.58 : x
2. Step 2: Convert to fraction form
   1,378.71/1,902.84 = 881.58/x
3. Step 3: Cross multiply
   1,378.71x = 1,902.84 × 881.58
4. Step 4: Simplify right side
   1,378.71x = 1,677,505.69
5. Step 5: Solve for x
   x = 1,677,505.69/1,378.71
6. Step 6: Final answer
   x = 1,216.72