Finding the Fourth Proportional to 31,139.32, 42,981.42 and 21,710.92

Step by Step Solution

1. Step 1: Write the proportion equation
   31,139.32 : 42,981.42 = 21,710.92 : x
2. Step 2: Convert to fraction form
   31,139.32/42,981.42 = 21,710.92/x
3. Step 3: Cross multiply
   31,139.32x = 42,981.42 × 21,710.92
4. Step 4: Simplify right side
   31,139.32x = 933,166,171.11
5. Step 5: Solve for x
   x = 933,166,171.11/31,139.32
6. Step 6: Final answer
   x = 29,967.46