Finding the Fourth Proportional to 13,281.72, 19,931.76 and 5,490.60

Step by Step Solution

1. Step 1: Write the proportion equation
   13,281.72 : 19,931.76 = 5,490.60 : x
2. Step 2: Convert to fraction form
   13,281.72/19,931.76 = 5,490.60/x
3. Step 3: Cross multiply
   13,281.72x = 19,931.76 × 5,490.60
4. Step 4: Simplify right side
   13,281.72x = 109,437,321.46
5. Step 5: Solve for x
   x = 109,437,321.46/13,281.72
6. Step 6: Final answer
   x = 8,239.69