Finding the Fourth Proportional to 1,139.78, 1,708.81 and 591.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.78 : 1,708.81 = 591.62 : x
2. Step 2: Convert to fraction form
   1,139.78/1,708.81 = 591.62/x
3. Step 3: Cross multiply
   1,139.78x = 1,708.81 × 591.62
4. Step 4: Simplify right side
   1,139.78x = 1,010,956.15
5. Step 5: Solve for x
   x = 1,010,956.15/1,139.78
6. Step 6: Final answer
   x = 886.97