Finding the Fourth Proportional to 15,856.41, 21,881.63 and 9,142.05

Step by Step Solution

1. Step 1: Write the proportion equation
   15,856.41 : 21,881.63 = 9,142.05 : x
2. Step 2: Convert to fraction form
   15,856.41/21,881.63 = 9,142.05/x
3. Step 3: Cross multiply
   15,856.41x = 21,881.63 × 9,142.05
4. Step 4: Simplify right side
   15,856.41x = 200,042,909.83
5. Step 5: Solve for x
   x = 200,042,909.83/15,856.41
6. Step 6: Final answer
   x = 12,615.90