Finding the Fourth Proportional to 12,421.56, 17,143.24 and 7,118.08

Step by Step Solution

1. Step 1: Write the proportion equation
   12,421.56 : 17,143.24 = 7,118.08 : x
2. Step 2: Convert to fraction form
   12,421.56/17,143.24 = 7,118.08/x
3. Step 3: Cross multiply
   12,421.56x = 17,143.24 × 7,118.08
4. Step 4: Simplify right side
   12,421.56x = 122,026,953.78
5. Step 5: Solve for x
   x = 122,026,953.78/12,421.56
6. Step 6: Final answer
   x = 9,823.80