Finding the Fourth Proportional to 31,142.30, 42,963.28 and 21,716.33

Step by Step Solution

1. Step 1: Write the proportion equation
   31,142.30 : 42,963.28 = 21,716.33 : x
2. Step 2: Convert to fraction form
   31,142.30/42,963.28 = 21,716.33/x
3. Step 3: Cross multiply
   31,142.30x = 42,963.28 × 21,716.33
4. Step 4: Simplify right side
   31,142.30x = 933,004,497.26
5. Step 5: Solve for x
   x = 933,004,497.26/31,142.30
6. Step 6: Final answer
   x = 29,959.40