Finding the Fourth Proportional to 28,156.48, 42,229.86 and 8,429.74

Step by Step Solution

1. Step 1: Write the proportion equation
   28,156.48 : 42,229.86 = 8,429.74 : x
2. Step 2: Convert to fraction form
   28,156.48/42,229.86 = 8,429.74/x
3. Step 3: Cross multiply
   28,156.48x = 42,229.86 × 8,429.74
4. Step 4: Simplify right side
   28,156.48x = 355,986,602.85
5. Step 5: Solve for x
   x = 355,986,602.85/28,156.48
6. Step 6: Final answer
   x = 12,643.15