Finding the Fourth Proportional to 288.10, 404.15 and 288.10

Step by Step Solution

1. Step 1: Write the proportion equation
   288.10 : 404.15 = 288.10 : x
2. Step 2: Convert to fraction form
   288.10/404.15 = 288.10/x
3. Step 3: Cross multiply
   288.10x = 404.15 × 288.10
4. Step 4: Simplify right side
   288.10x = 116,435.62
5. Step 5: Solve for x
   x = 116,435.62/288.10
6. Step 6: Final answer
   x = 404.15