Finding the Fourth Proportional to 1,139.98, 1,709.61 and 591.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.98 : 1,709.61 = 591.79 : x
2. Step 2: Convert to fraction form
   1,139.98/1,709.61 = 591.79/x
3. Step 3: Cross multiply
   1,139.98x = 1,709.61 × 591.79
4. Step 4: Simplify right side
   1,139.98x = 1,011,730.10
5. Step 5: Solve for x
   x = 1,011,730.10/1,139.98
6. Step 6: Final answer
   x = 887.50