Finding the Fourth Proportional to 13,145.14, 18,139.78 and 7,176.81

Step by Step Solution

1. Step 1: Write the proportion equation
   13,145.14 : 18,139.78 = 7,176.81 : x
2. Step 2: Convert to fraction form
   13,145.14/18,139.78 = 7,176.81/x
3. Step 3: Cross multiply
   13,145.14x = 18,139.78 × 7,176.81
4. Step 4: Simplify right side
   13,145.14x = 130,185,754.50
5. Step 5: Solve for x
   x = 130,185,754.50/13,145.14
6. Step 6: Final answer
   x = 9,903.72