Finding the Fourth Proportional to 13,505.71, 18,638.82 and 7,538.55

Step by Step Solution

1. Step 1: Write the proportion equation
   13,505.71 : 18,638.82 = 7,538.55 : x
2. Step 2: Convert to fraction form
   13,505.71/18,638.82 = 7,538.55/x
3. Step 3: Cross multiply
   13,505.71x = 18,638.82 × 7,538.55
4. Step 4: Simplify right side
   13,505.71x = 140,509,676.51
5. Step 5: Solve for x
   x = 140,509,676.51/13,505.71
6. Step 6: Final answer
   x = 10,403.72