Finding the Fourth Proportional to 12,905.61, 17,810.46 and 7,242.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,905.61 : 17,810.46 = 7,242.17 : x
2. Step 2: Convert to fraction form
   12,905.61/17,810.46 = 7,242.17/x
3. Step 3: Cross multiply
   12,905.61x = 17,810.46 × 7,242.17
4. Step 4: Simplify right side
   12,905.61x = 128,986,290.05
5. Step 5: Solve for x
   x = 128,986,290.05/12,905.61
6. Step 6: Final answer
   x = 9,994.59