Finding the Fourth Proportional to 12,986.72, 19,479.96 and 5,596.40

Step by Step Solution

1. Step 1: Write the proportion equation
   12,986.72 : 19,479.96 = 5,596.40 : x
2. Step 2: Convert to fraction form
   12,986.72/19,479.96 = 5,596.40/x
3. Step 3: Cross multiply
   12,986.72x = 19,479.96 × 5,596.40
4. Step 4: Simplify right side
   12,986.72x = 109,017,648.14
5. Step 5: Solve for x
   x = 109,017,648.14/12,986.72
6. Step 6: Final answer
   x = 8,394.55