Finding the Fourth Proportional to 3,479.64, 5,218.89 and 1,139.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,479.64 : 5,218.89 = 1,139.61 : x
2. Step 2: Convert to fraction form
   3,479.64/5,218.89 = 1,139.61/x
3. Step 3: Cross multiply
   3,479.64x = 5,218.89 × 1,139.61
4. Step 4: Simplify right side
   3,479.64x = 5,947,499.23
5. Step 5: Solve for x
   x = 5,947,499.23/3,479.64
6. Step 6: Final answer
   x = 1,709.23