Finding the Fourth Proportional to 66,020.72, 91,120.24 and 39,178.03

Step by Step Solution

1. Step 1: Write the proportion equation
   66,020.72 : 91,120.24 = 39,178.03 : x
2. Step 2: Convert to fraction form
   66,020.72/91,120.24 = 39,178.03/x
3. Step 3: Cross multiply
   66,020.72x = 91,120.24 × 39,178.03
4. Step 4: Simplify right side
   66,020.72x = 3,569,911,496.33
5. Step 5: Solve for x
   x = 3,569,911,496.33/66,020.72
6. Step 6: Final answer
   x = 54,072.59