Finding the Fourth Proportional to 31,138, 42,970.45 and 19,960

Step by Step Solution

1. Step 1: Write the proportion equation
   31,138 : 42,970.45 = 19,960 : x
2. Step 2: Convert to fraction form
   31,138/42,970.45 = 19,960/x
3. Step 3: Cross multiply
   31,138x = 42,970.45 × 19,960
4. Step 4: Simplify right side
   31,138x = 857,690,182
5. Step 5: Solve for x
   x = 857,690,182/31,138
6. Step 6: Final answer
   x = 27,544.81