Finding the Fourth Proportional to 1,005,087.38, 1,387,343.82 and 643,485.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005,087.38 : 1,387,343.82 = 643,485.15 : x
2. Step 2: Convert to fraction form
   1,005,087.38/1,387,343.82 = 643,485.15/x
3. Step 3: Cross multiply
   1,005,087.38x = 1,387,343.82 × 643,485.15
4. Step 4: Simplify right side
   1,005,087.38x = 892,735,142,896.85
5. Step 5: Solve for x
   x = 892,735,142,896.85/1,005,087.38
6. Step 6: Final answer
   x = 888,216.45