Finding the Fourth Proportional to 21,578.39, 29,777.82 and 12,018.02

Step by Step Solution

1. Step 1: Write the proportion equation
   21,578.39 : 29,777.82 = 12,018.02 : x
2. Step 2: Convert to fraction form
   21,578.39/29,777.82 = 12,018.02/x
3. Step 3: Cross multiply
   21,578.39x = 29,777.82 × 12,018.02
4. Step 4: Simplify right side
   21,578.39x = 357,870,287.43
5. Step 5: Solve for x
   x = 357,870,287.43/21,578.39
6. Step 6: Final answer
   x = 16,584.67