Finding the Fourth Proportional to 12,690.30, 17,518.74 and 8,448.42

Step by Step Solution

1. Step 1: Write the proportion equation
   12,690.30 : 17,518.74 = 8,448.42 : x
2. Step 2: Convert to fraction form
   12,690.30/17,518.74 = 8,448.42/x
3. Step 3: Cross multiply
   12,690.30x = 17,518.74 × 8,448.42
4. Step 4: Simplify right side
   12,690.30x = 148,005,673.39
5. Step 5: Solve for x
   x = 148,005,673.39/12,690.30
6. Step 6: Final answer
   x = 11,662.90