Finding the Fourth Proportional to 31,142.85, 42,964.05 and 21,716.88

Step by Step Solution

1. Step 1: Write the proportion equation
   31,142.85 : 42,964.05 = 21,716.88 : x
2. Step 2: Convert to fraction form
   31,142.85/42,964.05 = 21,716.88/x
3. Step 3: Cross multiply
   31,142.85x = 42,964.05 × 21,716.88
4. Step 4: Simplify right side
   31,142.85x = 933,045,118.16
5. Step 5: Solve for x
   x = 933,045,118.16/31,142.85
6. Step 6: Final answer
   x = 29,960.17