Finding the Fourth Proportional to 21,784.48, 29,866.78 and 21,390.82

Step by Step Solution

1. Step 1: Write the proportion equation
   21,784.48 : 29,866.78 = 21,390.82 : x
2. Step 2: Convert to fraction form
   21,784.48/29,866.78 = 21,390.82/x
3. Step 3: Cross multiply
   21,784.48x = 29,866.78 × 21,390.82
4. Step 4: Simplify right side
   21,784.48x = 638,874,786.82
5. Step 5: Solve for x
   x = 638,874,786.82/21,784.48
6. Step 6: Final answer
   x = 29,327.06