Finding the Fourth Proportional to 2,318.69, 3,478.49 and 2,086.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,318.69 : 3,478.49 = 2,086.31 : x
2. Step 2: Convert to fraction form
   2,318.69/3,478.49 = 2,086.31/x
3. Step 3: Cross multiply
   2,318.69x = 3,478.49 × 2,086.31
4. Step 4: Simplify right side
   2,318.69x = 7,257,222.38
5. Step 5: Solve for x
   x = 7,257,222.38/2,318.69
6. Step 6: Final answer
   x = 3,129.89