Finding the Fourth Proportional to 13,085.31, 18,057.85 and 7,117.10

Step by Step Solution

1. Step 1: Write the proportion equation
   13,085.31 : 18,057.85 = 7,117.10 : x
2. Step 2: Convert to fraction form
   13,085.31/18,057.85 = 7,117.10/x
3. Step 3: Cross multiply
   13,085.31x = 18,057.85 × 7,117.10
4. Step 4: Simplify right side
   13,085.31x = 128,519,524.24
5. Step 5: Solve for x
   x = 128,519,524.24/13,085.31
6. Step 6: Final answer
   x = 9,821.66