Finding the Fourth Proportional to 12,991.88, 17,919.60 and 12,797.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,991.88 : 17,919.60 = 12,797.48 : x
2. Step 2: Convert to fraction form
   12,991.88/17,919.60 = 12,797.48/x
3. Step 3: Cross multiply
   12,991.88x = 17,919.60 × 12,797.48
4. Step 4: Simplify right side
   12,991.88x = 229,325,719.42
5. Step 5: Solve for x
   x = 229,325,719.42/12,991.88
6. Step 6: Final answer
   x = 17,651.46