Finding the Fourth Proportional to 30,978.96, 46,470.20 and 8,790.58

Step by Step Solution

1. Step 1: Write the proportion equation
   30,978.96 : 46,470.20 = 8,790.58 : x
2. Step 2: Convert to fraction form
   30,978.96/46,470.20 = 8,790.58/x
3. Step 3: Cross multiply
   30,978.96x = 46,470.20 × 8,790.58
4. Step 4: Simplify right side
   30,978.96x = 408,500,010.72
5. Step 5: Solve for x
   x = 408,500,010.72/30,978.96
6. Step 6: Final answer
   x = 13,186.37