Finding the Fourth Proportional to 72,178.56, 99,602.32 and 39,911.28

Step by Step Solution

1. Step 1: Write the proportion equation
   72,178.56 : 99,602.32 = 39,911.28 : x
2. Step 2: Convert to fraction form
   72,178.56/99,602.32 = 39,911.28/x
3. Step 3: Cross multiply
   72,178.56x = 99,602.32 × 39,911.28
4. Step 4: Simplify right side
   72,178.56x = 3,975,256,082.17
5. Step 5: Solve for x
   x = 3,975,256,082.17/72,178.56
6. Step 6: Final answer
   x = 55,075.30