Finding the Fourth Proportional to 12,890.40, 17,788.32 and 9,741.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,890.40 : 17,788.32 = 9,741.12 : x
2. Step 2: Convert to fraction form
   12,890.40/17,788.32 = 9,741.12/x
3. Step 3: Cross multiply
   12,890.40x = 17,788.32 × 9,741.12
4. Step 4: Simplify right side
   12,890.40x = 173,278,159.72
5. Step 5: Solve for x
   x = 173,278,159.72/12,890.40
6. Step 6: Final answer
   x = 13,442.42