Finding the Fourth Proportional to 28,978.72, 39,987.94 and 16,403.47

Step by Step Solution

1. Step 1: Write the proportion equation
   28,978.72 : 39,987.94 = 16,403.47 : x
2. Step 2: Convert to fraction form
   28,978.72/39,987.94 = 16,403.47/x
3. Step 3: Cross multiply
   28,978.72x = 39,987.94 × 16,403.47
4. Step 4: Simplify right side
   28,978.72x = 655,940,974.15
5. Step 5: Solve for x
   x = 655,940,974.15/28,978.72
6. Step 6: Final answer
   x = 22,635.26