Finding the Fourth Proportional to 13,145.28, 18,138.72 and 7,556.64

Step by Step Solution

1. Step 1: Write the proportion equation
   13,145.28 : 18,138.72 = 7,556.64 : x
2. Step 2: Convert to fraction form
   13,145.28/18,138.72 = 7,556.64/x
3. Step 3: Cross multiply
   13,145.28x = 18,138.72 × 7,556.64
4. Step 4: Simplify right side
   13,145.28x = 137,067,777.10
5. Step 5: Solve for x
   x = 137,067,777.10/13,145.28
6. Step 6: Final answer
   x = 10,427.15