Finding the Fourth Proportional to 71,918.47, 99,243.39 and 40,086.28

Step by Step Solution

1. Step 1: Write the proportion equation
   71,918.47 : 99,243.39 = 40,086.28 : x
2. Step 2: Convert to fraction form
   71,918.47/99,243.39 = 40,086.28/x
3. Step 3: Cross multiply
   71,918.47x = 99,243.39 × 40,086.28
4. Step 4: Simplify right side
   71,918.47x = 3,978,298,319.69
5. Step 5: Solve for x
   x = 3,978,298,319.69/71,918.47
6. Step 6: Final answer
   x = 55,316.78