Finding the Fourth Proportional to 90.96, 136.42 and 42.84

Step by Step Solution

1. Step 1: Write the proportion equation
   90.96 : 136.42 = 42.84 : x
2. Step 2: Convert to fraction form
   90.96/136.42 = 42.84/x
3. Step 3: Cross multiply
   90.96x = 136.42 × 42.84
4. Step 4: Simplify right side
   90.96x = 5,844.23
5. Step 5: Solve for x
   x = 5,844.23/90.96
6. Step 6: Final answer
   x = 64.25