Finding the Fourth Proportional to 9,581.12, 13,221.60 and 5,389.28

Step by Step Solution

1. Step 1: Write the proportion equation
   9,581.12 : 13,221.60 = 5,389.28 : x
2. Step 2: Convert to fraction form
   9,581.12/13,221.60 = 5,389.28/x
3. Step 3: Cross multiply
   9,581.12x = 13,221.60 × 5,389.28
4. Step 4: Simplify right side
   9,581.12x = 71,254,904.45
5. Step 5: Solve for x
   x = 71,254,904.45/9,581.12
6. Step 6: Final answer
   x = 7,437.01