Finding the Fourth Proportional to 1,685.10, 2,322.90 and 1,311.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,685.10 : 2,322.90 = 1,311.42 : x
2. Step 2: Convert to fraction form
   1,685.10/2,322.90 = 1,311.42/x
3. Step 3: Cross multiply
   1,685.10x = 2,322.90 × 1,311.42
4. Step 4: Simplify right side
   1,685.10x = 3,046,297.52
5. Step 5: Solve for x
   x = 3,046,297.52/1,685.10
6. Step 6: Final answer
   x = 1,807.78