Finding the Fourth Proportional to 1,376.80, 1,899.05 and 1,081.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,376.80 : 1,899.05 = 1,081.55 : x
2. Step 2: Convert to fraction form
   1,376.80/1,899.05 = 1,081.55/x
3. Step 3: Cross multiply
   1,376.80x = 1,899.05 × 1,081.55
4. Step 4: Simplify right side
   1,376.80x = 2,053,916.87
5. Step 5: Solve for x
   x = 2,053,916.87/1,376.80
6. Step 6: Final answer
   x = 1,491.81