Finding the Fourth Proportional to 30,702.54, 42,369.57 and 18,128.10

Step by Step Solution

1. Step 1: Write the proportion equation
   30,702.54 : 42,369.57 = 18,128.10 : x
2. Step 2: Convert to fraction form
   30,702.54/42,369.57 = 18,128.10/x
3. Step 3: Cross multiply
   30,702.54x = 42,369.57 × 18,128.10
4. Step 4: Simplify right side
   30,702.54x = 768,079,801.92
5. Step 5: Solve for x
   x = 768,079,801.92/30,702.54
6. Step 6: Final answer
   x = 25,016.82