Finding the Fourth Proportional to 613,005.48, 919,513.35 and 213,645.61

Step by Step Solution

1. Step 1: Write the proportion equation
   613,005.48 : 919,513.35 = 213,645.61 : x
2. Step 2: Convert to fraction form
   613,005.48/919,513.35 = 213,645.61/x
3. Step 3: Cross multiply
   613,005.48x = 919,513.35 × 213,645.61
4. Step 4: Simplify right side
   613,005.48x = 196,449,990,563.89
5. Step 5: Solve for x
   x = 196,449,990,563.89/613,005.48
6. Step 6: Final answer
   x = 320,470.20