Finding the Fourth Proportional to 21,145.36, 31,718.56 and 7,105.59

Step by Step Solution

1. Step 1: Write the proportion equation
   21,145.36 : 31,718.56 = 7,105.59 : x
2. Step 2: Convert to fraction form
   21,145.36/31,718.56 = 7,105.59/x
3. Step 3: Cross multiply
   21,145.36x = 31,718.56 × 7,105.59
4. Step 4: Simplify right side
   21,145.36x = 225,379,047.22
5. Step 5: Solve for x
   x = 225,379,047.22/21,145.36
6. Step 6: Final answer
   x = 10,658.56