Finding the Fourth Proportional to 12,780.24, 17,622.18 and 9,002.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.24 : 17,622.18 = 9,002.20 : x
2. Step 2: Convert to fraction form
   12,780.24/17,622.18 = 9,002.20/x
3. Step 3: Cross multiply
   12,780.24x = 17,622.18 × 9,002.20
4. Step 4: Simplify right side
   12,780.24x = 158,638,388.80
5. Step 5: Solve for x
   x = 158,638,388.80/12,780.24
6. Step 6: Final answer
   x = 12,412.79