Finding the Fourth Proportional to 401,868.72, 553,986.72 and 306,209.52

Step by Step Solution

1. Step 1: Write the proportion equation
   401,868.72 : 553,986.72 = 306,209.52 : x
2. Step 2: Convert to fraction form
   401,868.72/553,986.72 = 306,209.52/x
3. Step 3: Cross multiply
   401,868.72x = 553,986.72 × 306,209.52
4. Step 4: Simplify right side
   401,868.72x = 169,636,007,617.57
5. Step 5: Solve for x
   x = 169,636,007,617.57/401,868.72
6. Step 6: Final answer
   x = 422,117.97