Finding the Fourth Proportional to 13,146.18, 18,131.49 and 7,839.87

Step by Step Solution

1. Step 1: Write the proportion equation
   13,146.18 : 18,131.49 = 7,839.87 : x
2. Step 2: Convert to fraction form
   13,146.18/18,131.49 = 7,839.87/x
3. Step 3: Cross multiply
   13,146.18x = 18,131.49 × 7,839.87
4. Step 4: Simplify right side
   13,146.18x = 142,148,524.51
5. Step 5: Solve for x
   x = 142,148,524.51/13,146.18
6. Step 6: Final answer
   x = 10,812.91