Finding the Fourth Proportional to 31,128.56, 42,954.51 and 17,697.20

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.56 : 42,954.51 = 17,697.20 : x
2. Step 2: Convert to fraction form
   31,128.56/42,954.51 = 17,697.20/x
3. Step 3: Cross multiply
   31,128.56x = 42,954.51 × 17,697.20
4. Step 4: Simplify right side
   31,128.56x = 760,174,339.60
5. Step 5: Solve for x
   x = 760,174,339.60/31,128.56
6. Step 6: Final answer
   x = 24,420.48