Finding the Fourth Proportional to 5,139.30, 7,707.43 and 2,672.79

Step by Step Solution

1. Step 1: Write the proportion equation
   5,139.30 : 7,707.43 = 2,672.79 : x
2. Step 2: Convert to fraction form
   5,139.30/7,707.43 = 2,672.79/x
3. Step 3: Cross multiply
   5,139.30x = 7,707.43 × 2,672.79
4. Step 4: Simplify right side
   5,139.30x = 20,600,341.83
5. Step 5: Solve for x
   x = 20,600,341.83/5,139.30
6. Step 6: Final answer
   x = 4,008.39