Finding the Fourth Proportional to 1,568.55, 2,164.60 and 860.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,568.55 : 2,164.60 = 860.40 : x
2. Step 2: Convert to fraction form
   1,568.55/2,164.60 = 860.40/x
3. Step 3: Cross multiply
   1,568.55x = 2,164.60 × 860.40
4. Step 4: Simplify right side
   1,568.55x = 1,862,406.72
5. Step 5: Solve for x
   x = 1,862,406.72/1,568.55
6. Step 6: Final answer
   x = 1,187.35