Finding the Fourth Proportional to 21,083.65, 31,621.89 and 7,042.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,083.65 : 31,621.89 = 7,042.09 : x
2. Step 2: Convert to fraction form
   21,083.65/31,621.89 = 7,042.09/x
3. Step 3: Cross multiply
   21,083.65x = 31,621.89 × 7,042.09
4. Step 4: Simplify right side
   21,083.65x = 222,684,195.35
5. Step 5: Solve for x
   x = 222,684,195.35/21,083.65
6. Step 6: Final answer
   x = 10,561.94