Finding the Fourth Proportional to 9,986.28, 13,781.10 and 5,509.81

Step by Step Solution

1. Step 1: Write the proportion equation
   9,986.28 : 13,781.10 = 5,509.81 : x
2. Step 2: Convert to fraction form
   9,986.28/13,781.10 = 5,509.81/x
3. Step 3: Cross multiply
   9,986.28x = 13,781.10 × 5,509.81
4. Step 4: Simplify right side
   9,986.28x = 75,931,242.59
5. Step 5: Solve for x
   x = 75,931,242.59/9,986.28
6. Step 6: Final answer
   x = 7,603.56