Finding the Fourth Proportional to 13,109.85, 18,091.75 and 7,141.57

Step by Step Solution

1. Step 1: Write the proportion equation
   13,109.85 : 18,091.75 = 7,141.57 : x
2. Step 2: Convert to fraction form
   13,109.85/18,091.75 = 7,141.57/x
3. Step 3: Cross multiply
   13,109.85x = 18,091.75 × 7,141.57
4. Step 4: Simplify right side
   13,109.85x = 129,203,499.05
5. Step 5: Solve for x
   x = 129,203,499.05/13,109.85
6. Step 6: Final answer
   x = 9,855.45