Finding the Fourth Proportional to 28,268.30, 42,355.29 and 12,449.78

Step by Step Solution

1. Step 1: Write the proportion equation
   28,268.30 : 42,355.29 = 12,449.78 : x
2. Step 2: Convert to fraction form
   28,268.30/42,355.29 = 12,449.78/x
3. Step 3: Cross multiply
   28,268.30x = 42,355.29 × 12,449.78
4. Step 4: Simplify right side
   28,268.30x = 527,314,042.34
5. Step 5: Solve for x
   x = 527,314,042.34/28,268.30
6. Step 6: Final answer
   x = 18,653.90