Finding the Fourth Proportional to 28,128.36, 42,196.86 and 8,404.68

Step by Step Solution

1. Step 1: Write the proportion equation
   28,128.36 : 42,196.86 = 8,404.68 : x
2. Step 2: Convert to fraction form
   28,128.36/42,196.86 = 8,404.68/x
3. Step 3: Cross multiply
   28,128.36x = 42,196.86 × 8,404.68
4. Step 4: Simplify right side
   28,128.36x = 354,651,105.30
5. Step 5: Solve for x
   x = 354,651,105.30/28,128.36
6. Step 6: Final answer
   x = 12,608.31