Finding the Fourth Proportional to 31,128.55, 42,957.20 and 17,699.80

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.55 : 42,957.20 = 17,699.80 : x
2. Step 2: Convert to fraction form
   31,128.55/42,957.20 = 17,699.80/x
3. Step 3: Cross multiply
   31,128.55x = 42,957.20 × 17,699.80
4. Step 4: Simplify right side
   31,128.55x = 760,333,733.21
5. Step 5: Solve for x
   x = 760,333,733.21/31,128.55
6. Step 6: Final answer
   x = 24,425.61