Finding the Fourth Proportional to 72,189.27, 99,618.32 and 39,921.79

Step by Step Solution

1. Step 1: Write the proportion equation
   72,189.27 : 99,618.32 = 39,921.79 : x
2. Step 2: Convert to fraction form
   72,189.27/99,618.32 = 39,921.79/x
3. Step 3: Cross multiply
   72,189.27x = 99,618.32 × 39,921.79
4. Step 4: Simplify right side
   72,189.27x = 3,976,941,451.58
5. Step 5: Solve for x
   x = 3,976,941,451.58/72,189.27
6. Step 6: Final answer
   x = 55,090.48