Finding the Fourth Proportional to 1,279.39, 1,766.42 and 860.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.39 : 1,766.42 = 860.37 : x
2. Step 2: Convert to fraction form
   1,279.39/1,766.42 = 860.37/x
3. Step 3: Cross multiply
   1,279.39x = 1,766.42 × 860.37
4. Step 4: Simplify right side
   1,279.39x = 1,519,774.78
5. Step 5: Solve for x
   x = 1,519,774.78/1,279.39
6. Step 6: Final answer
   x = 1,187.89