Finding the Fourth Proportional to 5,118.87, 7,061.90 and 3,128.79

Step by Step Solution

1. Step 1: Write the proportion equation
   5,118.87 : 7,061.90 = 3,128.79 : x
2. Step 2: Convert to fraction form
   5,118.87/7,061.90 = 3,128.79/x
3. Step 3: Cross multiply
   5,118.87x = 7,061.90 × 3,128.79
4. Step 4: Simplify right side
   5,118.87x = 22,095,186.46
5. Step 5: Solve for x
   x = 22,095,186.46/5,118.87
6. Step 6: Final answer
   x = 4,316.42