Finding the Fourth Proportional to 31,128.20, 42,955.24 and 17,697.60

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.20 : 42,955.24 = 17,697.60 : x
2. Step 2: Convert to fraction form
   31,128.20/42,955.24 = 17,697.60/x
3. Step 3: Cross multiply
   31,128.20x = 42,955.24 × 17,697.60
4. Step 4: Simplify right side
   31,128.20x = 760,204,655.42
5. Step 5: Solve for x
   x = 760,204,655.42/31,128.20
6. Step 6: Final answer
   x = 24,421.74