Finding the Fourth Proportional to 405,238.71, 607,314.69 and 315,389.90

Step by Step Solution

1. Step 1: Write the proportion equation
   405,238.71 : 607,314.69 = 315,389.90 : x
2. Step 2: Convert to fraction form
   405,238.71/607,314.69 = 315,389.90/x
3. Step 3: Cross multiply
   405,238.71x = 607,314.69 × 315,389.90
4. Step 4: Simplify right side
   405,238.71x = 191,540,916,311.06
5. Step 5: Solve for x
   x = 191,540,916,311.06/405,238.71
6. Step 6: Final answer
   x = 472,661.94