Finding the Fourth Proportional to 10,859.72, 14,978.68 and 9,966.34

Step by Step Solution

1. Step 1: Write the proportion equation
   10,859.72 : 14,978.68 = 9,966.34 : x
2. Step 2: Convert to fraction form
   10,859.72/14,978.68 = 9,966.34/x
3. Step 3: Cross multiply
   10,859.72x = 14,978.68 × 9,966.34
4. Step 4: Simplify right side
   10,859.72x = 149,282,604.39
5. Step 5: Solve for x
   x = 149,282,604.39/10,859.72
6. Step 6: Final answer
   x = 13,746.46