Finding the Fourth Proportional to 21,508.32, 29,680.72 and 12,077.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,508.32 : 29,680.72 = 12,077.28 : x
2. Step 2: Convert to fraction form
   21,508.32/29,680.72 = 12,077.28/x
3. Step 3: Cross multiply
   21,508.32x = 29,680.72 × 12,077.28
4. Step 4: Simplify right side
   21,508.32x = 358,462,366.04
5. Step 5: Solve for x
   x = 358,462,366.04/21,508.32
6. Step 6: Final answer
   x = 16,666.22