Finding the Fourth Proportional to 13,200.21, 18,216.54 and 7,231.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,200.21 : 18,216.54 = 7,231.50 : x
2. Step 2: Convert to fraction form
   13,200.21/18,216.54 = 7,231.50/x
3. Step 3: Cross multiply
   13,200.21x = 18,216.54 × 7,231.50
4. Step 4: Simplify right side
   13,200.21x = 131,732,909.01
5. Step 5: Solve for x
   x = 131,732,909.01/13,200.21
6. Step 6: Final answer
   x = 9,979.61