Finding the Fourth Proportional to 5,123.79, 7,688.09 and 2,657.27

Step by Step Solution

1. Step 1: Write the proportion equation
   5,123.79 : 7,688.09 = 2,657.27 : x
2. Step 2: Convert to fraction form
   5,123.79/7,688.09 = 2,657.27/x
3. Step 3: Cross multiply
   5,123.79x = 7,688.09 × 2,657.27
4. Step 4: Simplify right side
   5,123.79x = 20,429,356.78
5. Step 5: Solve for x
   x = 20,429,356.78/5,123.79
6. Step 6: Final answer
   x = 3,987.16