Finding the Fourth Proportional to 72,146.45, 99,589.89 and 64,579.43

Step by Step Solution

1. Step 1: Write the proportion equation
   72,146.45 : 99,589.89 = 64,579.43 : x
2. Step 2: Convert to fraction form
   72,146.45/99,589.89 = 64,579.43/x
3. Step 3: Cross multiply
   72,146.45x = 99,589.89 × 64,579.43
4. Step 4: Simplify right side
   72,146.45x = 6,431,458,329.96
5. Step 5: Solve for x
   x = 6,431,458,329.96/72,146.45
6. Step 6: Final answer
   x = 89,144.49