Finding the Fourth Proportional to 1,559.76, 2,152.40 and 861.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,559.76 : 2,152.40 = 861.12 : x
2. Step 2: Convert to fraction form
   1,559.76/2,152.40 = 861.12/x
3. Step 3: Cross multiply
   1,559.76x = 2,152.40 × 861.12
4. Step 4: Simplify right side
   1,559.76x = 1,853,474.69
5. Step 5: Solve for x
   x = 1,853,474.69/1,559.76
6. Step 6: Final answer
   x = 1,188.31