Finding the Fourth Proportional to 12,942.72, 17,861.41 and 7,909.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,942.72 : 17,861.41 = 7,909.18 : x
2. Step 2: Convert to fraction form
   12,942.72/17,861.41 = 7,909.18/x
3. Step 3: Cross multiply
   12,942.72x = 17,861.41 × 7,909.18
4. Step 4: Simplify right side
   12,942.72x = 141,269,071.98
5. Step 5: Solve for x
   x = 141,269,071.98/12,942.72
6. Step 6: Final answer
   x = 10,914.94