Finding the Fourth Proportional to 13,123.78, 18,110.42 and 7,155.56

Step by Step Solution

1. Step 1: Write the proportion equation
   13,123.78 : 18,110.42 = 7,155.56 : x
2. Step 2: Convert to fraction form
   13,123.78/18,110.42 = 7,155.56/x
3. Step 3: Cross multiply
   13,123.78x = 18,110.42 × 7,155.56
4. Step 4: Simplify right side
   13,123.78x = 129,590,233.27
5. Step 5: Solve for x
   x = 129,590,233.27/13,123.78
6. Step 6: Final answer
   x = 9,874.46