Finding the Fourth Proportional to 21,758.72, 30,035.39 and 12,806.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,758.72 : 30,035.39 = 12,806.60 : x
2. Step 2: Convert to fraction form
   21,758.72/30,035.39 = 12,806.60/x
3. Step 3: Cross multiply
   21,758.72x = 30,035.39 × 12,806.60
4. Step 4: Simplify right side
   21,758.72x = 384,651,011.36
5. Step 5: Solve for x
   x = 384,651,011.36/21,758.72
6. Step 6: Final answer
   x = 17,678.02