Finding the Fourth Proportional to 21,782.72, 30,065.06 and 13,287.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,782.72 : 30,065.06 = 13,287.72 : x
2. Step 2: Convert to fraction form
   21,782.72/30,065.06 = 13,287.72/x
3. Step 3: Cross multiply
   21,782.72x = 30,065.06 × 13,287.72
4. Step 4: Simplify right side
   21,782.72x = 399,496,099.06
5. Step 5: Solve for x
   x = 399,496,099.06/21,782.72
6. Step 6: Final answer
   x = 18,340.05