Finding the Fourth Proportional to 1,311.28, 1,807.89 and 1,074.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.28 : 1,807.89 = 1,074.35 : x
2. Step 2: Convert to fraction form
   1,311.28/1,807.89 = 1,074.35/x
3. Step 3: Cross multiply
   1,311.28x = 1,807.89 × 1,074.35
4. Step 4: Simplify right side
   1,311.28x = 1,942,307.11
5. Step 5: Solve for x
   x = 1,942,307.11/1,311.28
6. Step 6: Final answer
   x = 1,481.23