Finding the Fourth Proportional to 9,966.81, 13,754.29 and 5,490.57

Step by Step Solution

1. Step 1: Write the proportion equation
   9,966.81 : 13,754.29 = 5,490.57 : x
2. Step 2: Convert to fraction form
   9,966.81/13,754.29 = 5,490.57/x
3. Step 3: Cross multiply
   9,966.81x = 13,754.29 × 5,490.57
4. Step 4: Simplify right side
   9,966.81x = 75,518,864.59
5. Step 5: Solve for x
   x = 75,518,864.59/9,966.81
6. Step 6: Final answer
   x = 7,577.03