Finding the Fourth Proportional to 13,809.72, 19,056.72 and 7,840.62

Step by Step Solution

1. Step 1: Write the proportion equation
   13,809.72 : 19,056.72 = 7,840.62 : x
2. Step 2: Convert to fraction form
   13,809.72/19,056.72 = 7,840.62/x
3. Step 3: Cross multiply
   13,809.72x = 19,056.72 × 7,840.62
4. Step 4: Simplify right side
   13,809.72x = 149,416,499.97
5. Step 5: Solve for x
   x = 149,416,499.97/13,809.72
6. Step 6: Final answer
   x = 10,819.66