Finding the Fourth Proportional to 72,256.78, 99,718.23 and 40,423.78

Step by Step Solution

1. Step 1: Write the proportion equation
   72,256.78 : 99,718.23 = 40,423.78 : x
2. Step 2: Convert to fraction form
   72,256.78/99,718.23 = 40,423.78/x
3. Step 3: Cross multiply
   72,256.78x = 99,718.23 × 40,423.78
4. Step 4: Simplify right side
   72,256.78x = 4,030,987,791.51
5. Step 5: Solve for x
   x = 4,030,987,791.51/72,256.78
6. Step 6: Final answer
   x = 55,786.98