Finding the Fourth Proportional to 21,066.69, 31,589.45 and 7,021.80

Step by Step Solution

1. Step 1: Write the proportion equation
   21,066.69 : 31,589.45 = 7,021.80 : x
2. Step 2: Convert to fraction form
   21,066.69/31,589.45 = 7,021.80/x
3. Step 3: Cross multiply
   21,066.69x = 31,589.45 × 7,021.80
4. Step 4: Simplify right side
   21,066.69x = 221,814,800.01
5. Step 5: Solve for x
   x = 221,814,800.01/21,066.69
6. Step 6: Final answer
   x = 10,529.17