Finding the Fourth Proportional to 661,696.10, 992,058.15 and 262,139.30

Step by Step Solution

1. Step 1: Write the proportion equation
   661,696.10 : 992,058.15 = 262,139.30 : x
2. Step 2: Convert to fraction form
   661,696.10/992,058.15 = 262,139.30/x
3. Step 3: Cross multiply
   661,696.10x = 992,058.15 × 262,139.30
4. Step 4: Simplify right side
   661,696.10x = 260,057,429,000.30
5. Step 5: Solve for x
   x = 260,057,429,000.30/661,696.10
6. Step 6: Final answer
   x = 393,016.41