Finding the Fourth Proportional to 21,002.59, 31,431.21 and 17,210.53

Step by Step Solution

1. Step 1: Write the proportion equation
   21,002.59 : 31,431.21 = 17,210.53 : x
2. Step 2: Convert to fraction form
   21,002.59/31,431.21 = 17,210.53/x
3. Step 3: Cross multiply
   21,002.59x = 31,431.21 × 17,210.53
4. Step 4: Simplify right side
   21,002.59x = 540,947,625.49
5. Step 5: Solve for x
   x = 540,947,625.49/21,002.59
6. Step 6: Final answer
   x = 25,756.24