Finding the Fourth Proportional to 1,558.83, 2,151.18 and 860.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,558.83 : 2,151.18 = 860.21 : x
2. Step 2: Convert to fraction form
   1,558.83/2,151.18 = 860.21/x
3. Step 3: Cross multiply
   1,558.83x = 2,151.18 × 860.21
4. Step 4: Simplify right side
   1,558.83x = 1,850,463.86
5. Step 5: Solve for x
   x = 1,850,463.86/1,558.83
6. Step 6: Final answer
   x = 1,187.08