Finding the Fourth Proportional to 12,489.59, 17,236.29 and 7,185.21

Step by Step Solution

1. Step 1: Write the proportion equation
   12,489.59 : 17,236.29 = 7,185.21 : x
2. Step 2: Convert to fraction form
   12,489.59/17,236.29 = 7,185.21/x
3. Step 3: Cross multiply
   12,489.59x = 17,236.29 × 7,185.21
4. Step 4: Simplify right side
   12,489.59x = 123,846,325.58
5. Step 5: Solve for x
   x = 123,846,325.58/12,489.59
6. Step 6: Final answer
   x = 9,915.96