Finding the Fourth Proportional to 13,053.55, 18,013.88 and 7,085.21

Step by Step Solution

1. Step 1: Write the proportion equation
   13,053.55 : 18,013.88 = 7,085.21 : x
2. Step 2: Convert to fraction form
   13,053.55/18,013.88 = 7,085.21/x
3. Step 3: Cross multiply
   13,053.55x = 18,013.88 × 7,085.21
4. Step 4: Simplify right side
   13,053.55x = 127,632,087.29
5. Step 5: Solve for x
   x = 127,632,087.29/13,053.55
6. Step 6: Final answer
   x = 9,777.58