Finding the Fourth Proportional to 1,559.63, 2,152.29 and 861.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,559.63 : 2,152.29 = 861.05 : x
2. Step 2: Convert to fraction form
   1,559.63/2,152.29 = 861.05/x
3. Step 3: Cross multiply
   1,559.63x = 2,152.29 × 861.05
4. Step 4: Simplify right side
   1,559.63x = 1,853,229.30
5. Step 5: Solve for x
   x = 1,853,229.30/1,559.63
6. Step 6: Final answer
   x = 1,188.25