Finding the Fourth Proportional to 13,018.99, 17,966.55 and 7,980.31

Step by Step Solution

1. Step 1: Write the proportion equation
   13,018.99 : 17,966.55 = 7,980.31 : x
2. Step 2: Convert to fraction form
   13,018.99/17,966.55 = 7,980.31/x
3. Step 3: Cross multiply
   13,018.99x = 17,966.55 × 7,980.31
4. Step 4: Simplify right side
   13,018.99x = 143,378,705.54
5. Step 5: Solve for x
   x = 143,378,705.54/13,018.99
6. Step 6: Final answer
   x = 11,013.05