Finding the Fourth Proportional to 13,146.89, 18,142.56 and 7,178.81

Step by Step Solution

1. Step 1: Write the proportion equation
   13,146.89 : 18,142.56 = 7,178.81 : x
2. Step 2: Convert to fraction form
   13,146.89/18,142.56 = 7,178.81/x
3. Step 3: Cross multiply
   13,146.89x = 18,142.56 × 7,178.81
4. Step 4: Simplify right side
   13,146.89x = 130,241,900.44
5. Step 5: Solve for x
   x = 130,241,900.44/13,146.89
6. Step 6: Final answer
   x = 9,906.67