Finding the Fourth Proportional to 13,381.20, 18,462.72 and 7,717.68

Step by Step Solution

1. Step 1: Write the proportion equation
   13,381.20 : 18,462.72 = 7,717.68 : x
2. Step 2: Convert to fraction form
   13,381.20/18,462.72 = 7,717.68/x
3. Step 3: Cross multiply
   13,381.20x = 18,462.72 × 7,717.68
4. Step 4: Simplify right side
   13,381.20x = 142,489,364.89
5. Step 5: Solve for x
   x = 142,489,364.89/13,381.20
6. Step 6: Final answer
   x = 10,648.47