Finding the Fourth Proportional to 12,357.58, 18,538.18 and 3,921.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,357.58 : 18,538.18 = 3,921.28 : x
2. Step 2: Convert to fraction form
   12,357.58/18,538.18 = 3,921.28/x
3. Step 3: Cross multiply
   12,357.58x = 18,538.18 × 3,921.28
4. Step 4: Simplify right side
   12,357.58x = 72,693,360.38
5. Step 5: Solve for x
   x = 72,693,360.38/12,357.58
6. Step 6: Final answer
   x = 5,882.49