Finding the Fourth Proportional to 57,121.72, 78,936.42 and 42,949.96

Step by Step Solution

1. Step 1: Write the proportion equation
   57,121.72 : 78,936.42 = 42,949.96 : x
2. Step 2: Convert to fraction form
   57,121.72/78,936.42 = 42,949.96/x
3. Step 3: Cross multiply
   57,121.72x = 78,936.42 × 42,949.96
4. Step 4: Simplify right side
   57,121.72x = 3,390,316,081.54
5. Step 5: Solve for x
   x = 3,390,316,081.54/57,121.72
6. Step 6: Final answer
   x = 59,352.49