Finding the Fourth Proportional to 1,311.42, 1,798.02 and 1,288.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.42 : 1,798.02 = 1,288.02 : x
2. Step 2: Convert to fraction form
   1,311.42/1,798.02 = 1,288.02/x
3. Step 3: Cross multiply
   1,311.42x = 1,798.02 × 1,288.02
4. Step 4: Simplify right side
   1,311.42x = 2,315,885.72
5. Step 5: Solve for x
   x = 2,315,885.72/1,311.42
6. Step 6: Final answer
   x = 1,765.94