Finding the Fourth Proportional to 12,811.50, 19,207.89 and 8,641.14

Step by Step Solution

1. Step 1: Write the proportion equation
   12,811.50 : 19,207.89 = 8,641.14 : x
2. Step 2: Convert to fraction form
   12,811.50/19,207.89 = 8,641.14/x
3. Step 3: Cross multiply
   12,811.50x = 19,207.89 × 8,641.14
4. Step 4: Simplify right side
   12,811.50x = 165,978,066.59
5. Step 5: Solve for x
   x = 165,978,066.59/12,811.50
6. Step 6: Final answer
   x = 12,955.40