Finding the Fourth Proportional to 78,725.28, 108,640.80 and 42,915.36

Step by Step Solution

1. Step 1: Write the proportion equation
   78,725.28 : 108,640.80 = 42,915.36 : x
2. Step 2: Convert to fraction form
   78,725.28/108,640.80 = 42,915.36/x
3. Step 3: Cross multiply
   78,725.28x = 108,640.80 × 42,915.36
4. Step 4: Simplify right side
   78,725.28x = 4,662,359,042.69
5. Step 5: Solve for x
   x = 4,662,359,042.69/78,725.28
6. Step 6: Final answer
   x = 59,223.15