Finding the Fourth Proportional to 5,116.78, 7,061.25 and 2,879.20

Step by Step Solution

1. Step 1: Write the proportion equation
   5,116.78 : 7,061.25 = 2,879.20 : x
2. Step 2: Convert to fraction form
   5,116.78/7,061.25 = 2,879.20/x
3. Step 3: Cross multiply
   5,116.78x = 7,061.25 × 2,879.20
4. Step 4: Simplify right side
   5,116.78x = 20,330,751
5. Step 5: Solve for x
   x = 20,330,751/5,116.78
6. Step 6: Final answer
   x = 3,973.35