Finding the Fourth Proportional to 31,057.89, 42,848.97 and 20,309.06

Step by Step Solution

1. Step 1: Write the proportion equation
   31,057.89 : 42,848.97 = 20,309.06 : x
2. Step 2: Convert to fraction form
   31,057.89/42,848.97 = 20,309.06/x
3. Step 3: Cross multiply
   31,057.89x = 42,848.97 × 20,309.06
4. Step 4: Simplify right side
   31,057.89x = 870,222,088.42
5. Step 5: Solve for x
   x = 870,222,088.42/31,057.89
6. Step 6: Final answer
   x = 28,019.36