Finding the Fourth Proportional to 21,002.70, 31,467.60 and 13,603.35

Step by Step Solution

1. Step 1: Write the proportion equation
   21,002.70 : 31,467.60 = 13,603.35 : x
2. Step 2: Convert to fraction form
   21,002.70/31,467.60 = 13,603.35/x
3. Step 3: Cross multiply
   21,002.70x = 31,467.60 × 13,603.35
4. Step 4: Simplify right side
   21,002.70x = 428,064,776.46
5. Step 5: Solve for x
   x = 428,064,776.46/21,002.70
6. Step 6: Final answer
   x = 20,381.42