Finding the Fourth Proportional to 31,109, 42,930.42 and 19,931

Step by Step Solution

1. Step 1: Write the proportion equation
   31,109 : 42,930.42 = 19,931 : x
2. Step 2: Convert to fraction form
   31,109/42,930.42 = 19,931/x
3. Step 3: Cross multiply
   31,109x = 42,930.42 × 19,931
4. Step 4: Simplify right side
   31,109x = 855,646,201.02
5. Step 5: Solve for x
   x = 855,646,201.02/31,109
6. Step 6: Final answer
   x = 27,504.78