Finding the Fourth Proportional to 13,508.72, 18,642.31 and 7,540.64

Step by Step Solution

1. Step 1: Write the proportion equation
   13,508.72 : 18,642.31 = 7,540.64 : x
2. Step 2: Convert to fraction form
   13,508.72/18,642.31 = 7,540.64/x
3. Step 3: Cross multiply
   13,508.72x = 18,642.31 × 7,540.64
4. Step 4: Simplify right side
   13,508.72x = 140,574,836.42
5. Step 5: Solve for x
   x = 140,574,836.42/13,508.72
6. Step 6: Final answer
   x = 10,406.23