Finding the Fourth Proportional to 13,120.53, 18,105.78 and 7,152.06

Step by Step Solution

1. Step 1: Write the proportion equation
   13,120.53 : 18,105.78 = 7,152.06 : x
2. Step 2: Convert to fraction form
   13,120.53/18,105.78 = 7,152.06/x
3. Step 3: Cross multiply
   13,120.53x = 18,105.78 × 7,152.06
4. Step 4: Simplify right side
   13,120.53x = 129,493,624.91
5. Step 5: Solve for x
   x = 129,493,624.91/13,120.53
6. Step 6: Final answer
   x = 9,869.54