Finding the Fourth Proportional to 1,338.81, 2,008.55 and 1,081.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,338.81 : 2,008.55 = 1,081.15 : x
2. Step 2: Convert to fraction form
   1,338.81/2,008.55 = 1,081.15/x
3. Step 3: Cross multiply
   1,338.81x = 2,008.55 × 1,081.15
4. Step 4: Simplify right side
   1,338.81x = 2,171,535.43
5. Step 5: Solve for x
   x = 2,171,535.43/1,338.81
6. Step 6: Final answer
   x = 1,621.99