Finding the Fourth Proportional to 12,910.89, 19,329.84 and 8,219.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,910.89 : 19,329.84 = 8,219.28 : x
2. Step 2: Convert to fraction form
   12,910.89/19,329.84 = 8,219.28/x
3. Step 3: Cross multiply
   12,910.89x = 19,329.84 × 8,219.28
4. Step 4: Simplify right side
   12,910.89x = 158,877,367.32
5. Step 5: Solve for x
   x = 158,877,367.32/12,910.89
6. Step 6: Final answer
   x = 12,305.69