Finding the Fourth Proportional to 5,111.57, 7,055.31 and 3,123.80

Step by Step Solution

1. Step 1: Write the proportion equation
   5,111.57 : 7,055.31 = 3,123.80 : x
2. Step 2: Convert to fraction form
   5,111.57/7,055.31 = 3,123.80/x
3. Step 3: Cross multiply
   5,111.57x = 7,055.31 × 3,123.80
4. Step 4: Simplify right side
   5,111.57x = 22,039,377.38
5. Step 5: Solve for x
   x = 22,039,377.38/5,111.57
6. Step 6: Final answer
   x = 4,311.66