Finding the Fourth Proportional to 72,043.16, 99,407.67 and 40,212.05

Step by Step Solution

1. Step 1: Write the proportion equation
   72,043.16 : 99,407.67 = 40,212.05 : x
2. Step 2: Convert to fraction form
   72,043.16/99,407.67 = 40,212.05/x
3. Step 3: Cross multiply
   72,043.16x = 99,407.67 × 40,212.05
4. Step 4: Simplify right side
   72,043.16x = 3,997,386,196.42
5. Step 5: Solve for x
   x = 3,997,386,196.42/72,043.16
6. Step 6: Final answer
   x = 55,485.99