Finding the Fourth Proportional to 13,992.72, 21,008.52 and 8,147.76

Step by Step Solution

1. Step 1: Write the proportion equation
   13,992.72 : 21,008.52 = 8,147.76 : x
2. Step 2: Convert to fraction form
   13,992.72/21,008.52 = 8,147.76/x
3. Step 3: Cross multiply
   13,992.72x = 21,008.52 × 8,147.76
4. Step 4: Simplify right side
   13,992.72x = 171,172,378.92
5. Step 5: Solve for x
   x = 171,172,378.92/13,992.72
6. Step 6: Final answer
   x = 12,232.96