Finding the Fourth Proportional to 12,221.31, 16,864.56 and 7,185.75

Step by Step Solution

1. Step 1: Write the proportion equation
   12,221.31 : 16,864.56 = 7,185.75 : x
2. Step 2: Convert to fraction form
   12,221.31/16,864.56 = 7,185.75/x
3. Step 3: Cross multiply
   12,221.31x = 16,864.56 × 7,185.75
4. Step 4: Simplify right side
   12,221.31x = 121,184,512.02
5. Step 5: Solve for x
   x = 121,184,512.02/12,221.31
6. Step 6: Final answer
   x = 9,915.84