Finding the Fourth Proportional to 290.82, 435.86 and 128.52

Step by Step Solution

1. Step 1: Write the proportion equation
   290.82 : 435.86 = 128.52 : x
2. Step 2: Convert to fraction form
   290.82/435.86 = 128.52/x
3. Step 3: Cross multiply
   290.82x = 435.86 × 128.52
4. Step 4: Simplify right side
   290.82x = 56,016.73
5. Step 5: Solve for x
   x = 56,016.73/290.82
6. Step 6: Final answer
   x = 192.62