Finding the Fourth Proportional to 12,457.89, 17,213.76 and 9,960.62

Step by Step Solution

1. Step 1: Write the proportion equation
   12,457.89 : 17,213.76 = 9,960.62 : x
2. Step 2: Convert to fraction form
   12,457.89/17,213.76 = 9,960.62/x
3. Step 3: Cross multiply
   12,457.89x = 17,213.76 × 9,960.62
4. Step 4: Simplify right side
   12,457.89x = 171,459,636.06
5. Step 5: Solve for x
   x = 171,459,636.06/12,457.89
6. Step 6: Final answer
   x = 13,763.14