Finding the Fourth Proportional to 9,661.57, 13,333.20 and 5,412.78

Step by Step Solution

1. Step 1: Write the proportion equation
   9,661.57 : 13,333.20 = 5,412.78 : x
2. Step 2: Convert to fraction form
   9,661.57/13,333.20 = 5,412.78/x
3. Step 3: Cross multiply
   9,661.57x = 13,333.20 × 5,412.78
4. Step 4: Simplify right side
   9,661.57x = 72,169,678.30
5. Step 5: Solve for x
   x = 72,169,678.30/9,661.57
6. Step 6: Final answer
   x = 7,469.77