Finding the Fourth Proportional to 13,138.97, 18,128.39 and 7,830.03

Step by Step Solution

1. Step 1: Write the proportion equation
   13,138.97 : 18,128.39 = 7,830.03 : x
2. Step 2: Convert to fraction form
   13,138.97/18,128.39 = 7,830.03/x
3. Step 3: Cross multiply
   13,138.97x = 18,128.39 × 7,830.03
4. Step 4: Simplify right side
   13,138.97x = 141,945,837.55
5. Step 5: Solve for x
   x = 141,945,837.55/13,138.97
6. Step 6: Final answer
   x = 10,803.42