Finding the Fourth Proportional to 269.42, 404.05 and 86.78

Step by Step Solution

1. Step 1: Write the proportion equation
   269.42 : 404.05 = 86.78 : x
2. Step 2: Convert to fraction form
   269.42/404.05 = 86.78/x
3. Step 3: Cross multiply
   269.42x = 404.05 × 86.78
4. Step 4: Simplify right side
   269.42x = 35,061.00
5. Step 5: Solve for x
   x = 35,061.00/269.42
6. Step 6: Final answer
   x = 130.14