Finding the Fourth Proportional to 15,738.69, 21,719.48 and 8,665.12

Step by Step Solution

1. Step 1: Write the proportion equation
   15,738.69 : 21,719.48 = 8,665.12 : x
2. Step 2: Convert to fraction form
   15,738.69/21,719.48 = 8,665.12/x
3. Step 3: Cross multiply
   15,738.69x = 21,719.48 × 8,665.12
4. Step 4: Simplify right side
   15,738.69x = 188,201,748.61
5. Step 5: Solve for x
   x = 188,201,748.61/15,738.69
6. Step 6: Final answer
   x = 11,957.90