Finding the Fourth Proportional to 31,139, 42,971.83 and 19,961

Step by Step Solution

1. Step 1: Write the proportion equation
   31,139 : 42,971.83 = 19,961 : x
2. Step 2: Convert to fraction form
   31,139/42,971.83 = 19,961/x
3. Step 3: Cross multiply
   31,139x = 42,971.83 × 19,961
4. Step 4: Simplify right side
   31,139x = 857,760,698.63
5. Step 5: Solve for x
   x = 857,760,698.63/31,139
6. Step 6: Final answer
   x = 27,546.19