Finding the Fourth Proportional to 31,013.85, 42,811.27 and 21,986.39

Step by Step Solution

1. Step 1: Write the proportion equation
   31,013.85 : 42,811.27 = 21,986.39 : x
2. Step 2: Convert to fraction form
   31,013.85/42,811.27 = 21,986.39/x
3. Step 3: Cross multiply
   31,013.85x = 42,811.27 × 21,986.39
4. Step 4: Simplify right side
   31,013.85x = 941,265,278.62
5. Step 5: Solve for x
   x = 941,265,278.62/31,013.85
6. Step 6: Final answer
   x = 30,349.84