Finding the Fourth Proportional to 31,003.80, 42,784.74 and 16,857

Step by Step Solution

1. Step 1: Write the proportion equation
   31,003.80 : 42,784.74 = 16,857 : x
2. Step 2: Convert to fraction form
   31,003.80/42,784.74 = 16,857/x
3. Step 3: Cross multiply
   31,003.80x = 42,784.74 × 16,857
4. Step 4: Simplify right side
   31,003.80x = 721,222,362.18
5. Step 5: Solve for x
   x = 721,222,362.18/31,003.80
6. Step 6: Final answer
   x = 23,262.39