Finding the Fourth Proportional to 431,162.10, 646,743.15 and 221,210.10

Step by Step Solution

1. Step 1: Write the proportion equation
   431,162.10 : 646,743.15 = 221,210.10 : x
2. Step 2: Convert to fraction form
   431,162.10/646,743.15 = 221,210.10/x
3. Step 3: Cross multiply
   431,162.10x = 646,743.15 × 221,210.10
4. Step 4: Simplify right side
   431,162.10x = 143,066,116,885.82
5. Step 5: Solve for x
   x = 143,066,116,885.82/431,162.10
6. Step 6: Final answer
   x = 331,815.15