Finding the Fourth Proportional to 90.83, 136.31 and 42.09

Step by Step Solution

1. Step 1: Write the proportion equation
   90.83 : 136.31 = 42.09 : x
2. Step 2: Convert to fraction form
   90.83/136.31 = 42.09/x
3. Step 3: Cross multiply
   90.83x = 136.31 × 42.09
4. Step 4: Simplify right side
   90.83x = 5,737.08
5. Step 5: Solve for x
   x = 5,737.08/90.83
6. Step 6: Final answer
   x = 63.17