Finding the Fourth Proportional to 13,109.76, 18,091.89 and 7,141.68

Step by Step Solution

1. Step 1: Write the proportion equation
   13,109.76 : 18,091.89 = 7,141.68 : x
2. Step 2: Convert to fraction form
   13,109.76/18,091.89 = 7,141.68/x
3. Step 3: Cross multiply
   13,109.76x = 18,091.89 × 7,141.68
4. Step 4: Simplify right side
   13,109.76x = 129,206,488.98
5. Step 5: Solve for x
   x = 129,206,488.98/13,109.76
6. Step 6: Final answer
   x = 9,855.75