Finding the Fourth Proportional to 30,557.52, 42,171.33 and 17,128.78

Step by Step Solution

1. Step 1: Write the proportion equation
   30,557.52 : 42,171.33 = 17,128.78 : x
2. Step 2: Convert to fraction form
   30,557.52/42,171.33 = 17,128.78/x
3. Step 3: Cross multiply
   30,557.52x = 42,171.33 × 17,128.78
4. Step 4: Simplify right side
   30,557.52x = 722,343,348.23
5. Step 5: Solve for x
   x = 722,343,348.23/30,557.52
6. Step 6: Final answer
   x = 23,638.81