Finding the Fourth Proportional to 21,758.61, 30,029.29 and 12,808.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,758.61 : 30,029.29 = 12,808.31 : x
2. Step 2: Convert to fraction form
   21,758.61/30,029.29 = 12,808.31/x
3. Step 3: Cross multiply
   21,758.61x = 30,029.29 × 12,808.31
4. Step 4: Simplify right side
   21,758.61x = 384,624,498.45
5. Step 5: Solve for x
   x = 384,624,498.45/21,758.61
6. Step 6: Final answer
   x = 17,676.89