Finding the Fourth Proportional to 21,178.33, 31,768.31 and 7,139.01

Step by Step Solution

1. Step 1: Write the proportion equation
   21,178.33 : 31,768.31 = 7,139.01 : x
2. Step 2: Convert to fraction form
   21,178.33/31,768.31 = 7,139.01/x
3. Step 3: Cross multiply
   21,178.33x = 31,768.31 × 7,139.01
4. Step 4: Simplify right side
   21,178.33x = 226,794,282.77
5. Step 5: Solve for x
   x = 226,794,282.77/21,178.33
6. Step 6: Final answer
   x = 10,708.79