Finding the Fourth Proportional to 71,990.91, 99,347.31 and 40,157.91

Step by Step Solution

1. Step 1: Write the proportion equation
   71,990.91 : 99,347.31 = 40,157.91 : x
2. Step 2: Convert to fraction form
   71,990.91/99,347.31 = 40,157.91/x
3. Step 3: Cross multiply
   71,990.91x = 99,347.31 × 40,157.91
4. Step 4: Simplify right side
   71,990.91x = 3,989,580,333.72
5. Step 5: Solve for x
   x = 3,989,580,333.72/71,990.91
6. Step 6: Final answer
   x = 55,417.83