Finding the Fourth Proportional to 28,404.24, 39,196.05 and 15,656.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28,404.24 : 39,196.05 = 15,656.72 : x
2. Step 2: Convert to fraction form
   28,404.24/39,196.05 = 15,656.72/x
3. Step 3: Cross multiply
   28,404.24x = 39,196.05 × 15,656.72
4. Step 4: Simplify right side
   28,404.24x = 613,681,579.96
5. Step 5: Solve for x
   x = 613,681,579.96/28,404.24
6. Step 6: Final answer
   x = 21,605.28