Finding the Fourth Proportional to 30,739.56, 42,421.31 and 17,128.52

Step by Step Solution

1. Step 1: Write the proportion equation
   30,739.56 : 42,421.31 = 17,128.52 : x
2. Step 2: Convert to fraction form
   30,739.56/42,421.31 = 17,128.52/x
3. Step 3: Cross multiply
   30,739.56x = 42,421.31 × 17,128.52
4. Step 4: Simplify right side
   30,739.56x = 726,614,256.76
5. Step 5: Solve for x
   x = 726,614,256.76/30,739.56
6. Step 6: Final answer
   x = 23,637.76