Finding the Fourth Proportional to 57,128.72, 78,838.68 and 31,978.16

Step by Step Solution

1. Step 1: Write the proportion equation
   57,128.72 : 78,838.68 = 31,978.16 : x
2. Step 2: Convert to fraction form
   57,128.72/78,838.68 = 31,978.16/x
3. Step 3: Cross multiply
   57,128.72x = 78,838.68 × 31,978.16
4. Step 4: Simplify right side
   57,128.72x = 2,521,115,923.23
5. Step 5: Solve for x
   x = 2,521,115,923.23/57,128.72
6. Step 6: Final answer
   x = 44,130.45