Finding the Fourth Proportional to 5,285.89, 7,931.55 and 2,688.82

Step by Step Solution

1. Step 1: Write the proportion equation
   5,285.89 : 7,931.55 = 2,688.82 : x
2. Step 2: Convert to fraction form
   5,285.89/7,931.55 = 2,688.82/x
3. Step 3: Cross multiply
   5,285.89x = 7,931.55 × 2,688.82
4. Step 4: Simplify right side
   5,285.89x = 21,326,510.27
5. Step 5: Solve for x
   x = 21,326,510.27/5,285.89
6. Step 6: Final answer
   x = 4,034.61