Finding the Fourth Proportional to 28,379.94, 42,572.37 and 8,658.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28,379.94 : 42,572.37 = 8,658.72 : x
2. Step 2: Convert to fraction form
   28,379.94/42,572.37 = 8,658.72/x
3. Step 3: Cross multiply
   28,379.94x = 42,572.37 × 8,658.72
4. Step 4: Simplify right side
   28,379.94x = 368,622,231.57
5. Step 5: Solve for x
   x = 368,622,231.57/28,379.94
6. Step 6: Final answer
   x = 12,988.83