Finding the Fourth Proportional to 1,155.72, 1,593.92 and 861.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,155.72 : 1,593.92 = 861.69 : x
2. Step 2: Convert to fraction form
   1,155.72/1,593.92 = 861.69/x
3. Step 3: Cross multiply
   1,155.72x = 1,593.92 × 861.69
4. Step 4: Simplify right side
   1,155.72x = 1,373,460.62
5. Step 5: Solve for x
   x = 1,373,460.62/1,155.72
6. Step 6: Final answer
   x = 1,188.40