Finding the Fourth Proportional to 19,929.30, 29,878.56 and 12,916.32

Step by Step Solution

1. Step 1: Write the proportion equation
   19,929.30 : 29,878.56 = 12,916.32 : x
2. Step 2: Convert to fraction form
   19,929.30/29,878.56 = 12,916.32/x
3. Step 3: Cross multiply
   19,929.30x = 29,878.56 × 12,916.32
4. Step 4: Simplify right side
   19,929.30x = 385,921,042.10
5. Step 5: Solve for x
   x = 385,921,042.10/19,929.30
6. Step 6: Final answer
   x = 19,364.51