Finding the Fourth Proportional to 12,191.36, 18,261.52 and 7,786.40

Step by Step Solution

1. Step 1: Write the proportion equation
   12,191.36 : 18,261.52 = 7,786.40 : x
2. Step 2: Convert to fraction form
   12,191.36/18,261.52 = 7,786.40/x
3. Step 3: Cross multiply
   12,191.36x = 18,261.52 × 7,786.40
4. Step 4: Simplify right side
   12,191.36x = 142,191,388.55
5. Step 5: Solve for x
   x = 142,191,388.55/12,191.36
6. Step 6: Final answer
   x = 11,663.30