Finding the Fourth Proportional to 21,103.74, 29,118.69 and 12,603.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,103.74 : 29,118.69 = 12,603.60 : x
2. Step 2: Convert to fraction form
   21,103.74/29,118.69 = 12,603.60/x
3. Step 3: Cross multiply
   21,103.74x = 29,118.69 × 12,603.60
4. Step 4: Simplify right side
   21,103.74x = 367,000,321.28
5. Step 5: Solve for x
   x = 367,000,321.28/21,103.74
6. Step 6: Final answer
   x = 17,390.30